How severe is GHSA-4gcf-5m39-98mc?

GHSA-4gcf-5m39-98mc has a CVSS score of 8.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-4gcf-5m39-98mc?

GHSA-4gcf-5m39-98mc affects the following packages: github.com/woodpecker-ci/woodpecker (Go). Ecosystems affected: Go.

How do I fix GHSA-4gcf-5m39-98mc?

Update github.com/woodpecker-ci/woodpecker to 1.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4gcf-5m39-98mc is resolved across your whole dependency graph.

How do I detect GHSA-4gcf-5m39-98mc in my Go dependencies?

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

How do I mitigate GHSA-4gcf-5m39-98mc if there is no patch (or I can't update yet)?

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.

Is GHSA-4gcf-5m39-98mc actively exploited in the wild?

No public exploit code has been indexed for GHSA-4gcf-5m39-98mc 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-4gcf-5m39-98mc?

GHSA-4gcf-5m39-98mc has an EPSS (Exploit Prediction Scoring System) score of 0.9%, placing it in the 60th 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-4gcf-5m39-98mc?

GHSA-4gcf-5m39-98mc is classified as Improper Input Validation (CWE-20). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-4gcf-5m39-98mc published, and has it been updated?

GHSA-4gcf-5m39-98mc was published on August 16, 2023 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

HIGH severity

Woodpecker does not validate webhook before changing any dataGHSA-4gcf-5m39-98mc

HIGHFix: woodpecker-ci/woodpecker#2221

GHSA-4gcf-5m39-98mc is a high-severity (CVSS 8.1) Improper Input Validation vulnerability in github.com/woodpecker-ci/woodpecker. A fix is available for github.com/woodpecker-ci/woodpecker — see the affected versions and patch details below.

Also known asCVE-2023-40034GO-2023-2014

Published

Aug 16, 2023

Updated

Sep 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-4gcf-5m39-98mc.

EPSS Exploitation Probability

via FIRST.org ↗

0.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs60th percentile — riskier than 60% 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

1 pkg affected

🐹github.com/woodpecker-ci/woodpecker

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

Impact

An attacker can post malformed webhook data which leads to an update of the repository data that can e.g. allow the takeover of a repository. This is only critical if the CI is configured for public usage and connected to a forge witch is also in public usage.

Patches

Please use either next or the latest v1.0 e.g. v1.0.2

Workarounds

Secure the CI system by making it inaccessible to untrusted entities, for example, by placing it behind a firewall.

References

Fix: https://github.com/woodpecker-ci/woodpecker/pull/2221 Backport: https://github.com/woodpecker-ci/woodpecker/pull/2222

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/woodpecker-ci/woodpecker`	≥ 1.0.0&&< 1.0.2	1.0.2`go get github.com/woodpecker-ci/woodpecker@v1.0.2`

Affected Products

1 product · 1 configurations

Application

woodpeckerwoodpecker-ci

≥ 1.0.0 && < 1.0.2

range

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/woodpecker-ci/woodpecker, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/woodpecker-ci/woodpecker to 1.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4gcf-5m39-98mc is resolved across your whole dependency graph.
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.

Frequently Asked Questions

### Impact An attacker can post malformed webhook data which leads to an update of the repository data that can e.g. allow the takeover of a repository. This is only critical if the CI is configured for public usage and connected to a forge witch is also in public usage. ### Patches Please use either next or the latest v1.0 e.g. v1.0.2 ### Workarounds Secure the CI system by making it inaccessible to untrusted entities, for example, by placing it behind a firewall. ### References Fix: https://github.com/woodpecker-ci/woodpecker/pull/2221 Backport: https://github.com/woodpecker-ci/woodpecker