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UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-54167

An unauthenticated attacker who can reach the webhook endpoint can select an attacker-controlled host and cause the controller to send a locally signed GitHub App JWT to that service.

HIGH 8.2EPSS 0.27%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.27%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Pipelines-as-Code is a CI/CD system that lets users define Tekton pipelines in source code repositories. Prior to 0.37.8, 0.39.6, 0.42.1, and 0.48.0, the GitHub App provider accepts X-GitHub-Enterprise-Host as the API host while processing webhook events containing an installation.id, before webhook signature validation or confirmation that the host matches the repository URL in the signed payload. An unauthenticated attacker who can reach the webhook endpoint can select an attacker-controlled host and cause the controller to send a locally signed GitHub App JWT to that service. The exposed JWT may be used to attempt to mint installation access tokens during its validity window, subject to the GitHub App installation and permissions. The incoming webhook installation-lookup path is also affected, but exploitation of that path requires the valid incoming webhook secret for the target Repository CR. This issue is fixed in versions 0.37.8, 0.39.6, 0.42.1, and 0.48.0.

CVSS 3.1
8.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
EPSS
0.27% probability · 19th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-345
Source
security-advisories@github.com
EPSS trend
0%3%5%27 October 2026: 0.27%27 October 202627 October 2026

EPSS 0.3% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.