Vulnerabilities in pkg:maven/io.grpc/grpc-netty-shaded

PACKAGE
Advisory Identifier: GHSA-prj3-ccx8-p6x4
Advisory Summary

CVE-2025-55163 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting Netty codec http2 libraries in the Maven ecosystem. The issue involves netty affected by madeyoureset http/2 ddos vulnerability. Remediation is available by upgrading affected packages to version 4.2.4.Final, 4.1.124.Final, 1.75.0.

1 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:maven/io.grpc/grpc-netty-shaded

1 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:maven/io.grpc/grpc-netty-shaded. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-prj3-ccx8-p6x4 CVE-2025-55163 HIGH Netty affected by MadeYouReset HTTP/2 DDoS vulnerability

CVE-2025-55163 at a Glance

CVE Identifier CVE-2025-55163
GHSA Identifier GHSA-prj3-ccx8-p6x4
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-770: Allocation of Resources Without Limits or Throttling
Affected Product Netty codec http2
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2025-55163

To remediate this vulnerability, upgrade all affected Netty codec http2 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

io.netty:netty-codec-http2 fixed: 4.2.4.Final
<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-codec-http2</artifactId>
    <version>4.2.4.Final</version>
</dependency>
io.netty:netty-codec-http2 fixed: 4.1.124.Final
<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-codec-http2</artifactId>
    <version>4.1.124.Final</version>
</dependency>
io.grpc:grpc-netty-shaded fixed: 1.75.0
<dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-netty-shaded</artifactId>
    <version>1.75.0</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

mvn dependency:tree -Dincludes=io.netty

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2025-55163, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=io.netty

Analyze the terminal output to locate any version of Netty codec http2 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.2.4.Final), your application is affected.

Note: The mvn dependency:tree -Dincludes=io.netty command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-770: Allocation of Resources Without Limits or Throttling, where the product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. In Netty codec http2, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Below is a technical explanation of a newly discovered vulnerability in HTTP/2, which we refer to as “MadeYouReset.” ### MadeYouReset Vulnerability Summary The MadeYouReset DDoS vulnerability is a logical vulnerability in the HTTP/2 protocol, that uses malformed HTTP/2 control frames in order to break the max concurrent streams limit - which results in resource exhaustion and distributed denial of service. ### Mechanism The vulnerability uses malformed HTTP/2 control frames, or malformed flow, in order to make the server reset streams created by the client (using the RST_STREAM frame). The vulnerability could be triggered by several primitives, defined by the RFC of HTTP/2 (RFC 9113). The Primitives are: 1. WINDOW_UPDATE frame with an increment of 0 or an increment that makes the window exceed 2^31 - 1. (section 6.9 + 6.9.1) 2. HEADERS or DATA frames sent on a half-closed (remote) stream (which was closed using the END_STREAM flag). (note that for some implementations it's possible a CONTINUATION frame to trigger that as well - but it's very rare). (Section 5.1) 3. PRIORITY frame with a length other than 5. (section 6.3) From our experience, the primitives are likely to exist in the decreasing order listed above. Note that based on the implementation of the library, other primitives (which are not defined by the RFC) might exist - meaning scenarios in which RST_STREAM is not supposed to be sent, but in the implementation it does. On the other hand - some RFC-defined primitives might not work, even though they are defined by the RFC (as some implementations are not fully complying with RFC). For example, some implementations we’ve seen discard the PRIORITY frame - and thus does not return RST_STREAM, and some implementations send GO_AWAY when receiving a WINDOW_UPDATE frame with increment of 0. The vulnerability takes advantage of a design flaw in the HTTP/2 protocol - While HTTP/2 has a limit on the number of concurrently active streams per connection (which is usually 100, and is set by the parameter SETTINGS_MAX_CONCURRENT_STREAMS), the number of active streams is not counted correctly - when a stream is reset, it is immediately considered not active, and thus unaccounted for in the active streams counter. While the protocol does not count those streams as active, the server’s backend logic still processes and handles the requests that were canceled. Thus, the attacker can exploit this vulnerability to cause the server to handle an unbounded number of concurrent streams from a client on the same connection. The exploitation is very simple: the client issues a request in a stream, and then sends the control frame that causes the server to send a RST_STREAM. ### Attack Flow For example, a possible attack scenario can be: 1. Attacker opens an HTTP/2 connection to the server. 2. Attacker sends HEADERS frame with END_STREAM flag on a new stream X. 3. Attacker sends WINDOW_UPDATE for stream X with flow-control window of 0. 4. The server receives the WINDOW_UPDATE and immediately sends RST_STREAM for stream X to the client (+ decreases the active streams counter by 1). The attacker can repeat steps 2+3 as rapidly as it is capable, since the active streams counter never exceeds 1 and the attacker does not need to wait for the response from the server. This leads to resource exhaustion and distributed denial of service vulnerabilities with an impact of: CPU overload and/or memory exhaustion (implementation dependent) ### Comparison to Rapid Reset The vulnerability takes advantage of a design flow in the HTTP/2 protocol that was also used in the Rapid Reset vulnerability (CVE-2023-44487) which was exploited as a zero-day in the wild in August 2023 to October 2023, against multiple services and vendors. The Rapid Reset vulnerability uses RST_STREAM frames sent from the client, in order to create an unbounded amount of concurrent streams - it was given a CVSS score of 7.5. Rapid Reset was mostly mitigated by limiting the number/rate of RST_STREAM sent from the client, which does not mitigate the MadeYouReset attack - since it triggers the server to send a RST_STREAM. ### Suggested Mitigations for MadeYouReset A quick and easy mitigation will be to limit the number/rate of RST_STREAMs sent from the server. It is also possible to limit the number/rate of control frames sent by the client (e.g. WINDOW_UPDATE and PRIORITY), and treat protocol flow errors as a connection error. As mentioned in our previous message, this is a protocol-level vulnerability that affects multiple vendors and implementations. Given its broad impact, it is the shared responsibility of all parties involved to handle the disclosure process carefully and coordinate mitigations effectively. If you have any questions, we will be happy to clarify or schedule a Zoom call. Gal, Anat and Yaniv.

CVE-2025-55163 Affected Netty codec http2 Versions

3 component(s)
Fixed Versions:
4.2.4.Final4.1.124.Final1.75.0
Product / Package Ecosystem Affected Versions Fixed Version
io.netty:netty-codec-http2
Maven
≥ 4.2.0.Alpha1
< 4.2.4.Final
4.2.4.Final
io.netty:netty-codec-http2
Maven
< 4.1.124.Final
4.1.124.Final
io.grpc:grpc-netty-shaded
Maven
< 1.75.0
1.75.0

References

Frequently Asked Questions

What is CVE-2025-55163?
CVE-2025-55163 is a security vulnerability in Netty codec http2 involving Netty affected by MadeYouReset HTTP/2 DDoS vulnerability under CWE-770: Allocation of Resources Without Limits or Throttling.
Which Netty codec http2 versions are affected?
Affected versions include releases prior to 4.2.4.Final, 4.1.124.Final, 1.75.0 across affected packages: io.netty:netty-codec-http2, io.grpc:grpc-netty-shaded.
What version fixes CVE-2025-55163?
Upgrading to 4.2.4.Final, 4.1.124.Final, 1.75.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is netty-codec-http2 affected?
Yes, io.netty:netty-codec-http2 is affected in releases prior to 4.2.4.Final, 4.1.124.Final. Upgrade your dependency to 4.2.4.Final, 4.1.124.Final or later.
Is grpc-netty-shaded affected?
Yes, io.grpc:grpc-netty-shaded is affected in releases prior to 1.75.0. Upgrade your dependency to 1.75.0 or later.
What is the CVSS score of CVE-2025-55163?
CVE-2025-55163 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2025-55163?
CVE-2025-55163 is classified under CWE-770: Allocation of Resources Without Limits or Throttling (The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.).
How can I check Maven dependencies for CVE-2025-55163?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=io.netty'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-prj3-ccx8-p6x4",
  "modified" : "2025-11-05T20:38:22Z",
  "published" : "2025-08-13T19:06:56Z",
  "aliases" : [ "CVE-2025-55163" ],
  "summary" : "Netty affected by MadeYouReset HTTP/2 DDoS vulnerability",
  "details" : "Below is a technical explanation of a newly discovered vulnerability in HTTP/2, which we refer to as “MadeYouReset.”\n\n### MadeYouReset Vulnerability Summary\nThe MadeYouReset DDoS vulnerability is a logical vulnerability in the HTTP/2 protocol, that uses malformed HTTP/2 control frames in order to break the max concurrent streams limit - which results in resource exhaustion and distributed denial of service.\n\n### Mechanism\nThe vulnerability uses malformed HTTP/2 control frames, or malformed flow, in order to make the server reset streams created by the client (using the RST_STREAM frame). \nThe vulnerability could be triggered by several primitives, defined by the RFC of HTTP/2 (RFC 9113). The Primitives are:\n1. WINDOW_UPDATE frame with an increment of 0 or an increment that makes the window exceed 2^31 - 1. (section 6.9 + 6.9.1)\n2. HEADERS or DATA frames sent on a half-closed (remote) stream (which was closed using the END_STREAM flag). (note that for some implementations it's possible a CONTINUATION frame to trigger that as well - but it's very rare). (Section 5.1)\n3. PRIORITY frame with a length other than 5. (section 6.3)\nFrom our experience, the primitives are likely to exist in the decreasing order listed above.\nNote that based on the implementation of the library, other primitives (which are not defined by the RFC) might exist - meaning scenarios in which RST_STREAM is not supposed to be sent, but in the implementation it does. On the other hand - some RFC-defined primitives might not work, even though they are defined by the RFC (as some implementations are not fully complying with RFC). For example, some implementations we’ve seen discard the PRIORITY frame - and thus does not return RST_STREAM, and some implementations send GO_AWAY when receiving a WINDOW_UPDATE frame with increment of 0.\n\nThe vulnerability takes advantage of a design flaw in the HTTP/2 protocol - While HTTP/2 has a limit on the number of concurrently active streams per connection (which is usually 100, and is set by the parameter SETTINGS_MAX_CONCURRENT_STREAMS), the number of active streams is not counted correctly - when a stream is reset, it is immediately considered not active, and thus unaccounted for in the active streams counter. \nWhile the protocol does not count those streams as active, the server’s backend logic still processes and handles the requests that were canceled.\n\nThus, the attacker can exploit this vulnerability to cause the server to handle an unbounded number of concurrent streams from a client on the same connection. The exploitation is very simple: the client issues a request in a stream, and then sends the control frame that causes the server to send a RST_STREAM.\n\n### Attack Flow\nFor example, a possible attack scenario can be: \n1. Attacker opens an HTTP/2 connection to the server.\n2. Attacker sends HEADERS frame with END_STREAM flag on a new stream X.  \n3. Attacker sends WINDOW_UPDATE for stream X with flow-control window of 0.\n4. The server receives the WINDOW_UPDATE and immediately sends RST_STREAM for stream X to the client (+ decreases the active streams counter by 1).\n\nThe attacker can repeat steps 2+3 as rapidly as it is capable, since the active streams counter never exceeds 1 and the attacker does not need to wait for the response from the server.\nThis leads to resource exhaustion and distributed denial of service vulnerabilities with an impact of: CPU overload and/or memory exhaustion (implementation dependent)\n\n### Comparison to Rapid Reset\nThe vulnerability takes advantage of a design flow in the HTTP/2 protocol that was also used in the Rapid Reset vulnerability (CVE-2023-44487) which was exploited as a zero-day in the wild in August 2023 to October 2023, against multiple services and vendors.\nThe Rapid Reset vulnerability uses RST_STREAM frames sent from the client, in order to create an unbounded amount of concurrent streams - it was given a CVSS score of 7.5.\nRapid Reset was mostly mitigated by limiting the number/rate of RST_STREAM sent from the client, which does not mitigate the MadeYouReset attack - since it triggers the server to send a RST_STREAM.\n\n### Suggested Mitigations for MadeYouReset\nA quick and easy mitigation will be to limit the number/rate of RST_STREAMs sent from the server.\nIt is also possible to limit the number/rate of control frames sent by the client (e.g. WINDOW_UPDATE and PRIORITY), and treat protocol flow errors as a connection error.\n\nAs mentioned in our previous message, this is a protocol-level vulnerability that affects multiple vendors and implementations. Given its broad impact, it is the shared responsibility of all parties involved to handle the disclosure process carefully and coordinate mitigations effectively.\n\n\nIf you have any questions, we will be happy to clarify or schedule a Zoom call.\n\nGal, Anat and Yaniv.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
  } ],
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      "name" : "io.netty:netty-codec-http2"
    },
    "ranges" : [ {
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      "events" : [ {
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      }, {
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    "database_specific" : {
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    }
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      } ]
    } ],
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    }
  }, {
    "package" : {
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      "name" : "io.grpc:grpc-netty-shaded"
    },
    "ranges" : [ {
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      } ]
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  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/netty/netty/security/advisories/GHSA-prj3-ccx8-p6x4"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-55163"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/grpc/grpc-java/commit/6462ef9a11980e168c21d90bbc7245c728fd1a7a"
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    "url" : "https://github.com/netty/netty/commit/be53dc3c9acd9af2e20d0c3c07cd77115a594cf1"
  }, {
    "type" : "PACKAGE",
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  }, {
    "type" : "WEB",
    "url" : "https://www.kb.cert.org/vuls/id/767506"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2025/08/16/1"
  } ],
  "database_specific" : {
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    "github_reviewed_at" : "2025-08-13T19:06:56Z",
    "nvd_published_at" : "2025-08-13T15:15:39Z"
  }
}