CVE-2026-54167

HIGHPre-NVD 8.28.2
EchelonGraph scoreLOW confidence

This high-severity CVE scores 8.2 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: cna:github_m
8.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 8.2Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

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.

CVSS v3
8.2
EG Score
8.2(low)
EG Risk
41(Track)
EG Risk 41/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity82% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
—
EPSS %ILE
—
KEV
Not listed

Published

August 20, 2026

Last Modified

August 20, 2026

Vendor Advisories for CVE-2026-54167(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Data Freshness Timeline

(refreshed 1× in last 7d / 1× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-20 18:42 UTCEG score recompute

Frequently asked(4)

What is CVE-2026-54167?
CVE-2026-54167 is a high vulnerability published on August 20, 2026. Pipelines-as-Code GitHub App token request can be redirected via untrusted Enterprise Host header 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…
When was CVE-2026-54167 disclosed?
CVE-2026-54167 was first published in the National Vulnerability Database on August 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-54167?
CVE-2026-54167 has a CVSS v4.0 base score of 8.2 (CNA self-assessment; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-54167?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54167, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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