How severe is GHSA-cf3q-gqg7-3fm9?

GHSA-cf3q-gqg7-3fm9 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-cf3q-gqg7-3fm9?

GHSA-cf3q-gqg7-3fm9 affects the following packages: github.com/envoyproxy/envoy (Go), github.com/envoyproxy/envoy (Go), github.com/envoyproxy/envoy (Go), github.com/envoyproxy/envoy (Go). Ecosystems affected: Go.

How do I fix GHSA-cf3q-gqg7-3fm9?

Update github.com/envoyproxy/envoy to 1.30.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cf3q-gqg7-3fm9 is resolved across your whole dependency graph.

How do I detect GHSA-cf3q-gqg7-3fm9 in my Go dependencies?

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

How do I mitigate GHSA-cf3q-gqg7-3fm9 if there is no patch (or I can't update yet)?

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.

Is GHSA-cf3q-gqg7-3fm9 actively exploited in the wild?

No public exploit code has been indexed for GHSA-cf3q-gqg7-3fm9 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-cf3q-gqg7-3fm9?

GHSA-cf3q-gqg7-3fm9 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 38th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-cf3q-gqg7-3fm9?

GHSA-cf3q-gqg7-3fm9 is classified as CWE-460 (CWE-460). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-cf3q-gqg7-3fm9 published, and has it been updated?

GHSA-cf3q-gqg7-3fm9 was published on March 21, 2025 and was last updated on September 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

MEDIUM severity

Envoy crashes when HTTP ext_proc processes local repliesGHSA-cf3q-gqg7-3fm9

MEDIUMFix: envoyproxy/envoy@8eda1b8

GHSA-cf3q-gqg7-3fm9 is a medium-severity (CVSS 6.5) CWE-460 vulnerability in github.com/envoyproxy/envoy. A fix is available for github.com/envoyproxy/envoy — see the affected versions and patch details below.

Also known asBIT-envoy-2025-30157CVE-2025-30157

Published

Mar 21, 2025

Updated

Sep 10, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Exploitation data as of Nov 4, 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-cf3q-gqg7-3fm9.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs38th percentile — riskier than 38% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

4 pkgs affected

🐹github.com/envoyproxy/envoy🐹github.com/envoyproxy/envoy🐹github.com/envoyproxy/envoy🐹github.com/envoyproxy/envoy

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

Summary

Envoy's ext_proc HTTP filter is at risk of crashing if a local reply is sent to the external server due to the filter's life time issue. A known situation is the fail of a websocket handshake will trigger a local reply leading to the crash of Envoy.

PoC

If both websocket and ext_proc are enabled, a failed handshake will trigger a local reply, thus ext_proc will crash.

Mitigation

Disable websocket traffic
Change the websocket response from backend to always return 101 Switch protocol based on RFC.
Apply the patch and the ext_proc filter will not send the local reply that is generated by Envoy to the ext_proc server for processing.
Apply the patch that the router will cancel the upstream requests when sending a local reply.

Impact

Denial of service

Reporter

Vasilios Syrakis Fernando Cainelli

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/envoyproxy/envoy`	all versions	1.30.10`go get github.com/envoyproxy/envoy@v1.30.10`
🐹Go	`github.com/envoyproxy/envoy`	≥ 1.31.0&&< 1.31.6	1.31.6`go get github.com/envoyproxy/envoy@v1.31.6`
🐹Go	`github.com/envoyproxy/envoy`	≥ 1.32.0&&< 1.32.4	1.32.4`go get github.com/envoyproxy/envoy@v1.32.4`
🐹Go	`github.com/envoyproxy/envoy`	≥ 1.33.0&&< 1.33.1	1.33.1`go get github.com/envoyproxy/envoy@v1.33.1`

Affected Products

1 product · 4 configurations

Application

envoyenvoyproxy

≥ 1.32.0 && < 1.32.4

1 version

1.33.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/envoyproxy/envoy, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/envoyproxy/envoy to 1.30.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cf3q-gqg7-3fm9 is resolved across your whole dependency graph.
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

### Summary Envoy's ext_proc HTTP filter is at risk of crashing if a local reply is sent to the external server due to the filter's life time issue. A known situation is the fail of a websocket handshake will trigger a local reply leading to the crash of Envoy. ### PoC If both websocket and ext_proc are enabled, a failed handshake will trigger a local reply, thus ext_proc will crash. ### Mitigation 1. Disable websocket traffic 2. Change the websocket response from backend to always return `101 Switch protocol` based on RFC. 3. Apply the patch and the ext_proc filter will not send the local r

O3 Security · Impact-Aware SCA

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CVSS Score

6.5/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Raw vector

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

CWE Classification

CWE-460CWE-460

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

Timeline

Disclosed

Mar 21, 2025

Last updated

Sep 10, 2026

Identifiers

GHSA-cf3q-gqg7-3fm9

BIT-envoy-2025-30157

References

Advisorynvd.nist.gov · CVE 2025 30157 Webgithub.com · GHSA cf3q gqg7 3fm9 Webgithub.com · 8eda1b8ef5ba8663d16a737ab99458c039a9b53c Packagegithub.com · envoy

Related vulnerabilities

This CVE is medium severity; 7 of 8 other CVEs affecting envoy are rated as high or higher (top: high).

CVE-2026-26310CVE-2026-26309CVE-2026-26311CVE-2026-26330CVE-2026-26308CVE-2025-64527CVE-2025-64763CVE-2025-66220

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedSep 10, 2026

Envoy crashes when HTTP ext_proc processes local repliesGHSA-cf3q-gqg7-3fm9

Exploitation Status

Proof-of-concept exploit code exists

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Summary

PoC

Mitigation

Impact

Reporter

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is GHSA-cf3q-gqg7-3fm9 in your dependencies?