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GHSA-6xvm-j4wr-6v98 quinn-proto

Fix: quinn-rs/quinn#2559

GHSA-6xvm-j4wr-6v98 is a CWE-248 vulnerability in quinn-proto. A fix is available for quinn-proto — see the affected versions and patch details below.

Quinn affected by unauthenticated remote DoS via panic in QUIC transport parameter parsing

Also known asCVE-2026-31812RUSTSEC-2026-0037
Published
Mar 11, 2026
Updated
Sep 10, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 19, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for GHSA-6xvm-j4wr-6v98.

EPSS Exploitation Probability

via FIRST.org ↗
0.5%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs42th percentile — riskier than 42% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected
🦀quinn-proto

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.

Description

Summary

A remote, unauthenticated attacker can trigger a denial of service in applications using vulnerable quinn versions by sending a crafted QUIC Initial packet containing malformed quic_transport_parameters. In quinn-proto parsing logic, attacker-controlled varints are decoded with unwrap(), so truncated encodings cause Err(UnexpectedEnd) and panic. This is reachable over the network with a single packet and no prior trust or authentication.

Details

The issue is panic-on-untrusted-input in QUIC transport parameter parsing. In quinn-proto (observed in quinn-proto 0.11.13), parsing of some transport parameters uses a fallible varint decode followed by unwrap(). For malformed/truncated parameter values, decode returns UnexpectedEnd, and unwrap() panics.

Observed output:

thread 'tokio-rt-worker' (2366474) panicked at quinn-proto/src/transport_parameters.rs:473:67:
called `Result::unwrap()` on an `Err` value: UnexpectedEnd

PoC

Reproduces against the upstream Quinn server example.

  1. Start server:
cargo run --example server -- ./
  1. Prepare PoC client environment:
python3 -m venv .venv
source .venv/bin/activate
pip install aioquic
  1. Run PoC script attack.py against server QUIC listener (default example target shown):
python attack.py

Observed output

thread 'tokio-rt-worker' (2366903) panicked at quinn-proto/src/transport_parameters.rs:473:67:
called `Result::unwrap()` on an `Err` value: UnexpectedEnd

Impact

Vulnerability type: Remote Denial of Service (panic/crash) Attack requirements: Network reachability to UDP QUIC listener Authentication/privileges: None Who is impacted: Any server/application using affected quinn/quinn-proto versions where this parse path is reachable; process-level impact depends on integration panic handling policy

This vulnerability was originally submitted by @revofusion to the Ethereum Foundation bug bounty program

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🦀crates.ioquinn-protoall versions0.11.14cargo update -p quinn-proto --precise 0.11.14

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for quinn-proto, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update quinn-proto to 0.11.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6xvm-j4wr-6v98 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-6xvm-j4wr-6v98 can be triaged on real exposure rather than presence alone.

Tailored to GHSA-6xvm-j4wr-6v98. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

The availability impact of this flaw is limited to specific services on Red Hat systems. Host system availability is not at risk.

ProductFixed inAdvisory
Logging Subsystem for Red Hat OpenShift 6.4openshift-logging/vector-rhel9:1780052069RHSA-2026:22862
Red Hat Ansible Automation Platform 2.6ansible-automation-platform-26/lightspeed-chatbot-rhel9:1777398576RHSA-2026:13545
Red Hat OpenShift AI 3.3rhoai/odh-model-registry-job-async-upload-rhel9:1778596806RHSA-2026:19712
Red Hat Trusted Artifact Signer 1.3rhtas/tuffer-rhel9:1773307309RHSA-2026:5459

Frequently Asked Questions

### Summary A remote, unauthenticated attacker can trigger a denial of service in applications using vulnerable `quinn` versions by sending a crafted QUIC Initial packet containing malformed `quic_transport_parameters`. `In quinn-proto` parsing logic, attacker-controlled varints are decoded with `unwrap()`, so truncated encodings cause `Err(UnexpectedEnd)` and `panic`. This is reachable over the network with a single packet and no prior trust or authentication. ### Details The issue is panic-on-untrusted-input in QUIC transport parameter parsing. In `quinn-proto` (observed in `quinn-proto 0.1
O3 Security · Impact-Aware SCA

Is GHSA-6xvm-j4wr-6v98 in your dependencies?

O3 Security finds GHSA-6xvm-j4wr-6v98 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-6xvm-j4wr-6v98: quinn-proto DoS | O3 Security