How severe is GHSA-f5f4-3hh4-f54m?

GHSA-f5f4-3hh4-f54m has a CVSS score of 8.2/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-f5f4-3hh4-f54m?

GHSA-f5f4-3hh4-f54m affects the following packages: github.com/openshift-pipelines/pipelines-as-code (Go), github.com/openshift-pipelines/pipelines-as-code (Go), github.com/openshift-pipelines/pipelines-as-code (Go), github.com/openshift-pipelines/pipelines-as-code (Go). Ecosystems affected: Go.

How do I fix GHSA-f5f4-3hh4-f54m?

Update github.com/openshift-pipelines/pipelines-as-code to 0.48.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f5f4-3hh4-f54m is resolved across your whole dependency graph.

How do I detect GHSA-f5f4-3hh4-f54m in my Go dependencies?

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

How do I mitigate GHSA-f5f4-3hh4-f54m 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-f5f4-3hh4-f54m actively exploited in the wild?

No public exploit code has been indexed for GHSA-f5f4-3hh4-f54m 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-f5f4-3hh4-f54m?

GHSA-f5f4-3hh4-f54m has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 17th 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-f5f4-3hh4-f54m?

GHSA-f5f4-3hh4-f54m is classified as CWE-345 (CWE-345). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-f5f4-3hh4-f54m published, and has it been updated?

GHSA-f5f4-3hh4-f54m was published on August 20, 2026 and was last updated on August 26, 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

GHSA-f5f4-3hh4-f54m — pipelines-as-code

HIGH

GHSA-f5f4-3hh4-f54m is a high-severity (CVSS 8.2) CWE-345 vulnerability in github.com/openshift-pipelines/pipelines-as-code. A fix is available for github.com/openshift-pipelines/pipelines-as-code — see the affected versions and patch details below.

Pipelines-as-Code GitHub App token request can be redirected via untrusted Enterprise Host header

Also known asCVE-2026-54167GO-2026-6266

Published

Aug 20, 2026

Updated

Aug 26, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Exploitation data as of Oct 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
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-f5f4-3hh4-f54m.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs17th percentile — riskier than 17% of all scored CVEsHighest risk

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

How urgent is this, really

GHSA-f5f4-3hh4-f54m by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 383,485 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

4 pkgs affected

🐹github.com/openshift-pipelines/pipelines-as-code🐹github.com/openshift-pipelines/pipelines-as-code🐹github.com/openshift-pipelines/pipelines-as-code🐹github.com/openshift-pipelines/pipelines-as-code

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

Pipelines-as-Code installations using the GitHub App provider are vulnerable to GitHub App credential exfiltration through the webhook endpoint.

Affected versions accepted the X-GitHub-Enterprise-Host request header as the GitHub Enterprise API host during GitHub App token generation. For GitHub webhook events containing an installation.id, Pipelines-as-Code generated a GitHub App JWT and requested an installation access token before validating the webhook signature or checking that the Enterprise host matched the repository URL in the signed payload.

An attacker who can reach the Pipelines-as-Code webhook endpoint can send a crafted GitHub webhook payload containing an installation ID and set X-GitHub-Enterprise-Host to an attacker-controlled host. During token generation, the controller signs a GitHub App JWT locally and sends it to the selected API host. This can disclose the GitHub App JWT to the attacker-controlled service, allowing the attacker to attempt to mint GitHub App installation access tokens within the JWT validity window, subject to the GitHub App installation and permissions.

The incoming webhook flow also trusted X-GitHub-Enterprise-Host during GitHub App installation lookup and token generation. In that path, exploitation requires a valid incoming webhook secret for the target Repository CR.

Patches

The fix validates the webhook signature before GitHub App token generation, verifies that X-GitHub-Enterprise-Host matches the repository URL in the webhook payload, and stops using the request header to select the GitHub Enterprise host for incoming webhook token requests. For incoming webhooks, the Enterprise host is derived from the configured Repository URL instead.

The fix is available in v0.48.0. Supported backport releases will be added here after release tags are published.

Workarounds

Until a patched release is deployed, operators should block or strip unexpected X-GitHub-Enterprise-Host headers at the ingress or proxy in front of the Pipelines-as-Code webhook endpoint. For GitHub.com installations, reject requests that include this header. For GitHub Enterprise Server installations, allow only the expected Enterprise hostname.

Operators should also restrict access to the webhook endpoint to trusted Git provider sources where possible. If exploitation is suspected, rotate the GitHub App private key and review GitHub App installation token activity.

Credits

Reported and fixed by the Pipelines-as-Code maintainers.

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/openshift-pipelines/pipelines-as-code`	≥ 0.43.0&&< 0.48.0	0.48.0`go get github.com/openshift-pipelines/pipelines-as-code@v0.48.0`
🐹Go	`github.com/openshift-pipelines/pipelines-as-code`	≥ 0.40.0&&< 0.42.1	0.42.1`go get github.com/openshift-pipelines/pipelines-as-code@v0.42.1`
🐹Go	`github.com/openshift-pipelines/pipelines-as-code`	≥ 0.38.0&&< 0.39.6	0.39.6`go get github.com/openshift-pipelines/pipelines-as-code@v0.39.6`
🐹Go	`github.com/openshift-pipelines/pipelines-as-code`	all versions	0.37.8`go get github.com/openshift-pipelines/pipelines-as-code@v0.37.8`

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/openshift-pipelines/pipelines-as-code, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/openshift-pipelines/pipelines-as-code to 0.48.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f5f4-3hh4-f54m 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.

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

This flaw has an Important impact because vulnerable Pipelines-as-Code GitHub App webhook deployments can disclose a locally signed GitHub App JWT to an attacker-controlled host. An unauthenticated remote attacker who can reach the webhook endpoint can supply an untrusted Enterprise-host header; the exposed JWT may…

Workaround published by Red Hat

Until a patched release is deployed, block or strip unexpected X-GitHub-Enterprise-Host headers at the ingress or proxy in front of the Pipelines-as-Code webhook endpoint. For GitHub.com installations, reject requests containing this header; for GitHub Enterprise Server, permit only the expected hostname. Restrict webhook access to trusted Git provider sources where possible, and rotate the GitHub App private key if compromise is suspected.

Source: Red Hat security advisory for GHSA-f5f4-3hh4-f54m (CC BY 4.0)

Frequently Asked Questions

## Impact Pipelines-as-Code installations using the GitHub App provider are vulnerable to GitHub App credential exfiltration through the webhook endpoint. Affected versions accepted the `X-GitHub-Enterprise-Host` request header as the GitHub Enterprise API host during GitHub App token generation. For GitHub webhook events containing an `installation.id`, Pipelines-as-Code generated a GitHub App JWT and requested an installation access token before validating the webhook signature or checking that the Enterprise host matched the repository URL in the signed payload. An attacker who can reach