quic-go: Panic occurs when queuing undecryptable packets after handshake completion

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2025-59530: 0.46% estimated exploitation activity in the next 30 days; percentile 40.33 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A misbehaving or malicious server can trigger an assertion in a quic-go client (and crash the process) by sending a premature HANDSHAKEDONE frame during the handshake. Impact A misbehaving or malicious server can cause a denial-of-service (DoS) attack on the quic-go client by triggering an assertion failure, leading to a process crash. This requires no authentication and can be exploited during the handshake phase. Observed in the wild with certain server implementations (e.g. Solana's Firedancer QUIC). Affected Versions - All versions prior to v0.49.1 (for the 0.49 branch) - Versions v0.50.0 to v0.54.0 (inclusive) - Fixed in v0.49.1, v0.54.1, and v0.55.0 onward Users are recommended to upgrade to the latest patched version in their respective maintenance branch or to v0.55.0 or later. Details For a regular 1-RTT handshake, QUIC uses three sets of keys to encrypt / decrypt QUIC packets: - Initial keys (derived from a static key and the connection ID) - Handshake keys (derived…

Published by the source

10 Oct 2025, 17:03 UTC

Last modified by the source

5 Nov 2025, 22:06 UTC

Source last checked

26 Oct 2026, 15:13 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-47m2-4cr7-mhcw

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# Patch Next advisory brief: CVE-2025-59530

Advisory: quic-go: Panic occurs when queuing undecryptable packets after handshake completion
IDs: CVE-2025-59530, GHSA-47m2-4cr7-mhcw
Record: https://patchnext.com/advisories/cve-2025-59530 (revision 1, source checked 26 Oct 2026, 15:13 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/quic-go/quic-go 0.54.1, 0.49.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/quic-go/quic-go: affected < 0.49.1; >= 0.50.0, < 0.54.1; fixed in 0.54.1, 0.49.1

## Suggested inspection (read-only)
- Go github.com/quic-go/quic-go: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/quic-go/quic-go.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-47m2-4cr7-mhcw (GitHub-reviewed advisory GHSA-47m2-4cr7-mhcw lists affected ranges: Go github.com/quic-go/quic-go >=0 =0.50.0 <0.54.1)

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