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

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

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.

Source published

15 Sep 2026 14:29:45 UTC

Source modified

15 Sep 2026 14:49:57 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

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

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.

Source published

Sep 15, 2026, 2:29:45 PM (timezone not stated)

Source modified

Sep 15, 2026, 2:49:57 PM (timezone not stated)

Observed here

30 Oct 2026 09:50:25 UTC

Source terms

ENISA EUVD · source terms and attribution apply

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

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

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.

Source published

15 Sep 2026 15:17:17 UTC

Source modified

30 Sep 2026 17:43:24 UTC

Observed here

25 Oct 2026 13:17:22 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

## 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. ## 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.

Source published

20 Aug 2026 18:36:30 UTC

Source modified

28 Oct 2026 15:45:10 UTC

Observed here

28 Oct 2026 15:48:49 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Publisher rating · HIGH

Pipelines-as-Code GitHub App token request can be redirected via untrusted Enterprise Host header in github.com/openshift-pipelines/pipelines-as-code

Source published

25 Aug 2026 19:43:10 UTC

Source modified

26 Aug 2026 01:21:40 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.