CVE-2025-64702: Github.com/quic go/quic go Denial of Service Vulnerability
MODERATECVE-2025-64702 is a MODERATE (CVSS 5.3) denial of service vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting Github.com/quic go/quic go libraries in the Go ecosystem. The issue involves quic-go http/3 qpack header expansion dos. Remediation is available by upgrading affected packages to version 0.57.0.
CVE-2025-64702 at a Glance
Security Impact
CVSS: 5.3
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:L).
How to Fix CVE-2025-64702
To remediate this vulnerability, upgrade all affected Github.com/quic go/quic go dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/quic-go/quic-go to 0.57.0Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/quic-go/quic-goHow to Check if You Are Affected
To determine whether your application is affected by CVE-2025-64702, inspect your project dependencies for Github.com/quic go/quic go:
inspect dependencies for github.com/quic-go/quic-goAnalyze the terminal output to locate any version of Github.com/quic go/quic go in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.57.0), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
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 Github.com/quic go/quic go, 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
CVE-2025-64702 Affected Github.com/quic go/quic go Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/quic-go/quic-go
|
Go |
< 0.57.0
|
0.57.0
|
References
Frequently Asked Questions
What is CVE-2025-64702?
Which Github.com/quic go/quic go versions are affected?
What version fixes CVE-2025-64702?
Is github.com/quic-go/quic-go affected?
What is the CVSS score of CVE-2025-64702?
What CWE is associated with CVE-2025-64702?
How can I check Go dependencies for CVE-2025-64702?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-g754-hx8w-x2g6",
"modified" : "2025-12-17T00:36:27Z",
"published" : "2025-12-11T16:48:27Z",
"aliases" : [ "CVE-2025-64702" ],
"summary" : "quic-go HTTP/3 QPACK Header Expansion DoS",
"details" : "## Summary\n\nAn attacker can cause excessive memory allocation in quic-go's HTTP/3 client and server implementations by sending a QPACK-encoded HEADERS frame that decodes into a large header field section (many unique header names and/or large values). The implementation builds an `http.Header` (used on the `http.Request` and `http.Response`, respectively), while only enforcing limits on the size of the (QPACK-compressed) HEADERS frame, but not on the decoded header, leading to memory exhaustion.\n\n## Impact\n\nA misbehaving or malicious peer can cause a denial-of-service (DoS) attack on quic-go's HTTP/3 servers or clients by triggering excessive memory allocation, potentially leading to crashes or exhaustion. It affects both servers and clients due to symmetric header construction.\n\n## Details\n\nIn HTTP/3, headers are compressed using QPACK (RFC 9204). quic-go's HTTP/3 server (and client) decodes the QPACK-encoded HEADERS frame into header fields, then constructs an http.Request (or response).\n\n`http3.Server.MaxHeaderBytes` and `http3.Transport.MaxResponseHeaderBytes`, respectively, limit encoded HEADERS frame size (default: 1 MB server, 10 MB client), but not decoded size. A maliciously crafted HEADERS frame can expand to ~50x the encoded size using QPACK static table entries with long names / values.\n\nRFC 9114 requires enforcing decoded field section size limits via SETTINGS, which quic-go did not do.\n\n## The Fix\n\nquic-go now enforces RFC 9114 decoded field section size limits, sending SETTINGS_MAX_FIELD_SECTION_SIZE and using incremental QPACK decoding to check the header size after each entry, aborting early on violations with HTTP 431 (on the server side) and stream reset (on the client side).",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/quic-go/quic-go"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "0.57.0"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/quic-go/quic-go/security/advisories/GHSA-g754-hx8w-x2g6"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-64702"
}, {
"type" : "WEB",
"url" : "https://github.com/quic-go/quic-go/commit/5b2d2129f8315da41e01eff0a847ab38a34e83a8"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/quic-go/quic-go"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-770" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2025-12-11T16:48:27Z",
"nvd_published_at" : "2025-12-11T21:15:54Z"
}
}