CVE-2026-84784: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-4fx9-95x6-pq4q
Share
CVSS 7.5
CWE-770
Published
Advisory Summary

CVE-2026-84784 is a HIGH (CVSS 7.5) security vulnerability vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting Software libraries in the Maven ecosystem. The weakness occurs when 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.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-84784 at a Glance

CVE Identifier CVE-2026-84784
GHSA Identifier GHSA-4fx9-95x6-pq4q
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-770: Allocation of Resources Without Limits or Throttling
Affected Product Software
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-2026-84784

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

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

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-84784, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

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

Note: The mvn dependency:tree 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 Software, 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

Issue summary: A malicious remote peer may flood the local QUIC stack with NEW_CONNECTION_ID frames by avoiding a limit check on how many connection IDs the remote QUIC stack can use. Impact summary: The local QUIC stack sends a RETIRE_CONN_ID frame for every NEW_CONNECTION_ID frame it receives. The RETIRE_CONN_ID frame is dispatched via the Control Frame Queue (CFQ). If the remote peer also withholds ACKs, then it can force the local stack to allocate ~400MB (depending on ACK delay). CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: RFC 9000 sections 5.1.1 and 5.1.2 [1] describe the mechanism by which a remote peer can notify the local QUIC stack to change the destination connection ID (a.k.a. CID) the local stack uses to identify the connection at the remote peer. Each CID is associated with a sequence number. The sequence number is transmitted in NEW_CONNECTION_ID and RETIRE_CONNECTION_ID frames to identify the CID which is being either associated with a connection or retired. The remote peer sends a NEW_CONNECTION_ID frame to let the local stack know a new CID is being associated with an existing connection. The NEW_CONNECTION_ID frame carries the new CID, its sequence number, and the retire-prior-to number. The retire-prior-to identifies existing CIDs that are to be retired. The local QUIC stack must send a RETIRE_CONNECTION_ID for every destination CID whose sequence number is less than retire-prior-to. The CID becomes retired after the local stack receives an ACK for its RETIRE_CONNECTION_ID frame. Although the OpenSSL QUIC stack supports at most one destination CID for every connection, it can be tricked into processing more than one RETIRE_CONNECTION_ID frame per connection. The OpenSSL QUIC stack currently retires the destination CID as soon as it receives the NEW_CONNECTION_ID, while in fact the destination CID must be retired after an ACK for the RETIRE_CONNECTION_ID frame is received. Correcting the flawed logic also fixes the backlog growth. [1] https://datatracker.ietf.org/doc/html/rfc9000#name-issuing-connection-ids FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.

References

NVD — CVE-2026-84784 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-84784
Security Fix Commit FIX COMMIT
https://github.com/openssl/openssl/commit/4685c914b0d410b1034f40b547c95bc95e7a380a
Security Fix Commit FIX COMMIT
https://github.com/openssl/openssl/commit/9a30fe0fba195c14e5b87bf93c0d0fdb70373806
Security Fix Commit FIX COMMIT
https://github.com/openssl/openssl/commit/dba3c48d653c64fcbc9070a17a0ee2b3e2f3af1f
Security Fix Commit FIX COMMIT
https://github.com/openssl/openssl/commit/e9e5155833fa968bee50024bf9ca3a185ab599fe
openssl-library.org/news/secadv/2026092... WEB
https://openssl-library.org/news/secadv/20260929.txt

Frequently Asked Questions

What is CVE-2026-84784?
CVE-2026-84784 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-770: Allocation of Resources Without Limits or Throttling.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-84784?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-84784?
CVE-2026-84784 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-2026-84784?
CVE-2026-84784 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-2026-84784?
Run the dependency tree command: 'mvn dependency:tree'. 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
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-4fx9-95x6-pq4q",
  "modified" : "2026-09-29T18:31:45Z",
  "published" : "2026-09-29T18:31:45Z",
  "aliases" : [ "CVE-2026-84784" ],
  "details" : "Issue summary: A malicious remote peer may flood the local QUIC\nstack with NEW_CONNECTION_ID frames by avoiding a limit check on\nhow many connection IDs the remote QUIC stack can use.\n\nImpact summary: The local QUIC stack sends a RETIRE_CONN_ID frame\nfor every NEW_CONNECTION_ID frame it receives. The RETIRE_CONN_ID\nframe is dispatched via the Control Frame Queue (CFQ). If the remote\npeer also withholds ACKs, then it can force the local stack\nto allocate ~400MB (depending on ACK delay).\n\nCWE: CWE-770: Allocation of Resources Without Limits or Throttling\n\nDescription: RFC 9000 sections 5.1.1 and 5.1.2 [1] describe the mechanism\nby which a remote peer can notify the local QUIC stack to change the\ndestination connection ID (a.k.a. CID) the local stack uses to\nidentify the connection at the remote peer. Each CID is associated\nwith a sequence number. The sequence number is transmitted\nin NEW_CONNECTION_ID and RETIRE_CONNECTION_ID frames to identify the CID\nwhich is being either associated with a connection or retired.\n\nThe remote peer sends a NEW_CONNECTION_ID frame to let the local stack know\na new CID is being associated with an existing connection. The\nNEW_CONNECTION_ID frame carries the new CID, its sequence number, and the\nretire-prior-to number. The retire-prior-to identifies existing\nCIDs that are to be retired. The local QUIC stack must send a\nRETIRE_CONNECTION_ID for every destination CID whose sequence number\nis less than retire-prior-to. The CID becomes retired after the\nlocal stack receives an ACK for its RETIRE_CONNECTION_ID frame.\n\nAlthough the OpenSSL QUIC stack supports at most one destination CID\nfor every connection, it can be tricked into processing more than\none RETIRE_CONNECTION_ID frame per connection. The OpenSSL QUIC\nstack currently retires the destination CID as soon as it receives\nthe NEW_CONNECTION_ID, while in fact the destination CID must\nbe retired after an ACK for the RETIRE_CONNECTION_ID frame is received.\nCorrecting the flawed logic also fixes the backlog growth.\n\n[1] https://datatracker.ietf.org/doc/html/rfc9000#name-issuing-connection-ids\n\nFIPS impact: no\nThe FIPS module is not affected as the QUIC implementation is outside of\nthe OpenSSL FIPS module boundary.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-84784"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/openssl/openssl/commit/4685c914b0d410b1034f40b547c95bc95e7a380a"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/openssl/openssl/commit/9a30fe0fba195c14e5b87bf93c0d0fdb70373806"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/openssl/openssl/commit/dba3c48d653c64fcbc9070a17a0ee2b3e2f3af1f"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/openssl/openssl/commit/e9e5155833fa968bee50024bf9ca3a185ab599fe"
  }, {
    "type" : "WEB",
    "url" : "https://openssl-library.org/news/secadv/20260929.txt"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-770" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-29T16:17:12Z"
  }
}