CVE-2026-54167Network attack vector

GitHub App JWT disclosure via untrusted host header

Published Sep 15, 2026 · Updated Sep 15, 2026

Credential disclosure in Tekton Pipelines as Code affected releases allows remote attackers to steal a GitHub App JWT through its webhook. The GitHub App webhook path trusts X-GitHub-Enterprise-Host to select the API host, then signs and sends a JWT before validating the webhook signature or matching the host to the signed repository URL. Webhook reachability is sufficient for the installation.id path; the JWT permits installation-token requests only during its validity window and within the GitHub App installation permissions.

CVSS severity8.2
High
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Credential disclosure in Tekton Pipelines as Code affected releases allows remote attackers to steal a GitHub App JWT through its webhook. The GitHub App webhook path trusts X-GitHub-Enterprise-Host to select the API host, then signs and sends a JWT before validating the webhook signature or matching the host to the signed repository URL. Webhook reachability is sufficient for the installation.id path; the JWT permits installation-token requests only during its validity window and within the GitHub App installation permissions.

The record

CVE
CVE-2026-54167
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
Tekton
Product
Pipelines as Code
Classifications
CWE-345, T1528
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.37.8
  2. Affected versionversion=>= 0.38.0, < 0.39.6
  3. Affected versionversion=>= 0.40.0, < 0.42.1
  4. Affected versionversion=>= 0.43.0, < 0.48.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Tekton · Pipelines as Codeversion=< 0.37.8; version=>= 0.38.0, < 0.39.6; version=>= 0.40.0, < 0.42.1; version=>= 0.43.0, < 0.48.0

Published CVSS scores

8.2GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-345Insufficient Verification of Data Authenticity
T1528Steal Application Access Token

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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