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HIGH severity

CVE-2021-39162 — pomerium

HIGH

CVE-2021-39162 is a high-severity (CVSS 8.6) CWE-754 vulnerability in github.com/pomerium/pomerium. A fix is available for github.com/pomerium/pomerium — see the affected versions and patch details below.

Incorrect handling of H2 GOAWAY + SETTINGS frames

Also known asBIT-envoy-2021-39162GHSA-gjcg-vrxg-xmgvGO-2022-0933
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Oct 2, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
1.6%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs75th percentile — riskier than 75% of all scored CVEsHighest risk
0.17%0.82%1.48%2.14%0.7%1.6%Apr 26Aug 26Oct 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-39162 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected
🐹github.com/pomerium/pomerium

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

Description

Envoy, which Pomerium is based on, can abnormally terminate if an H/2 GOAWAY and SETTINGS frame are received in the same IO event.

Impact

This can lead to a DoS in the presence of untrusted upstream servers.

Patches

0.15.1 contains an upgraded envoy binary with this vulnerability patched.

Workarounds

If only trusted upstreams are configured, there is not substantial risk of this condition being triggered.

References

envoy GSA envoy CVE envoy announcement

For more information

If you have any questions or comments about this advisory:

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/pomerium/pomeriumall versions0.15.1go get github.com/pomerium/pomerium@v0.15.1

Affected Products

2 products · 3 configurations
Application
envoyenvoyproxy
< 1.18.4
1 version
1.19.0
Application
pomeriumpomerium
1 version
0.15.0

Detection & mitigation playbook

Open-source dependency

  1. Detect

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

  2. Fix

    Update github.com/pomerium/pomerium to 0.15.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-39162 is resolved across your whole dependency graph.

  3. Workarounds

    Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

Envoy, which Pomerium is based on, can abnormally terminate if an H/2 GOAWAY and SETTINGS frame are received in the same IO event. ### Impact This can lead to a DoS in the presence of untrusted *upstream* servers. ### Patches 0.15.1 contains an upgraded envoy binary with this vulnerability patched. ### Workarounds If only trusted upstreams are configured, there is not substantial risk of this condition being triggered. ### References [envoy GSA](https://github.com/envoyproxy/envoy/security/advisories/GHSA-j374-mjrw-vvp8) [envoy CVE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021
O3 Security · Impact-Aware SCA

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CVE-2021-39162: pomerium DoS — Fixed in 0.15.1