What is the CVSS score of EUVD-2026-33340?

EUVD-2026-33340 has a contested CVSS base score of 9.1 from a third party (e.g. CISA-ADP), while the vendor rates it Critical. vuln.today uses the vendor rating as authoritative.

Which versions of GitHub CLI are affected by EUVD-2026-33340?

GitHub CLI (gh) versions before 2.93.0 leak authentication tokens to third-party cloud hosts during attestation and release verification operations, potentially exposing repository access credentials…. A patch is available.

How to fix or mitigate EUVD-2026-33340?

Within 24 hours: inventory all gh CLI installations across development workstations and CI/CD systems to identify versions prior to 2.93.0. Within 7 days: deploy GitHub CLI version 2.93.0 or later to all affected systems and verify deployment completion. Within 30 days: rotate all GitHub.com and enterprise repository tokens; audit access logs from tuf-repo-cdn.sigstore.dev and Azure blob storage services for unauthorized credential usage; confirm no anomalous repository access occurred during the vulnerable exposure window.

GitHub CLI EUVD-2026-33340

| CVE-2026-48501 CRITICAL

Incorrect Authorization (CWE-863)

2026-05-29 https://github.com/cli/cli

GHSA-8xvp-7hj6-mcj9

Authentication Bypass Microsoft

Critical

Disputed · 9.1 NVD

Severity by source

Sources disagree (Medium–Critical)

NVD PRIMARY

9.1 CRITICAL

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

vuln.today AI

6.8 MEDIUM

Passive token disclosure requires the victim to run specific commands (UI:R) and the attacker to observe traffic/logs on third-party hosts (AC:H); a captured full-scope token yields C:H and downstream I:H, no availability impact.

3.1 AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

4.0 AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

SUSE

7.4 HIGH

AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Red Hat

6.8 MEDIUM

qualitative

vuln.today treats the vendor’s rating as authoritative. A higher third-party CVSS (e.g. CISA-ADP) is shown for transparency but does not drive the headline severity.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Lifecycle Timeline

Analysis Updated

Jul 21, 2026 - 15:43 vuln.today

v2 (cvss_changed)

Re-analysis Queued

Jul 21, 2026 - 15:37 vuln.today

cvss_changed

Severity Changed

Jul 21, 2026 - 15:37 NVD

HIGH CRITICAL

CVSS changed

Jul 21, 2026 - 15:37 NVD

7.4 (HIGH) 9.1 (CRITICAL)

Patch available

May 29, 2026 - 17:02 EUVD

Source Code Evidence Fetched

May 29, 2026 - 15:50 vuln.today

Analysis Generated

May 29, 2026 - 15:50 vuln.today

CVE Published

May 29, 2026 - 15:30 nvd

HIGH 7.4

DescriptionNVD

Summary

GitHub CLI incorrectly includes an authorization header in API requests to TUF repository mirrors via gh attestation, gh release verify, and gh release verify-asset commands.

Affected users:

Authenticated github.com users who previously ran gh attestation commands, gh release verify, or gh release verify-asset: the github.com token was included in requests to tuf-repo.github.com, a GitHub Pages domain that is not a GitHub API endpoint. All authentication types are affected.
Users with GH_ENTERPRISE_TOKEN or GITHUB_ENTERPRISE_TOKEN set who previously ran gh attestation commands, gh release verify, or gh release verify-asset: the enterprise token was included in requests to external hosts tuf-repo-cdn.sigstore.dev and tmaproduction.blob.core.windows.net. These hosts are not operated by GitHub.

Details

The CLI uses a shared HTTP client with an authentication layer that automatically attaches tokens to outgoing requests. This layer lacks accurate host detection and can incorrectly attribute the target host, providing it with a token it should never receive.

Specifically, the host normalization logic collapses any *.github.com subdomain to github.com, so a request to tuf-repo.github.com (a GitHub Pages site, not a GitHub API endpoint) is treated as a request to github.com and receives the user's github.com token. For hosts that don't match github.com or a known GHES instance at all, the resolver falls back to GH_ENTERPRISE_TOKEN if set.

The gh attestation, gh release verify and gh release verify-asset commands fetch data from several external hosts as part of their normal operation (TUF metadata from tuf-repo.github.com and tuf-repo-cdn.sigstore.dev, artifact bundles from Azure Blob Storage). Because these requests go through the same authenticated HTTP client, the token is sent to all of them.

Impact

Tokens were transmitted in HTTP headers to the listed hosts during normal gh attestation, gh release verify, and gh release verify-asset operations. There is no evidence that tokens were logged, retained, or accessed by unauthorized parties. If a token were captured, it would grant the same access as the token holder, potentially including private repositories, organization resources, or enterprise administration depending on token type and permissions.

Remediation and mitigation

Revoke authentication tokens used with the GitHub CLI:

Upgrade gh to 2.93.0.
Review personal security logs and any relevant audit logs for actions associated with personal or enterprise accounts.

AnalysisAI

Credential exposure in GitHub CLI (gh) versions prior to 2.93.0 causes the authenticated HTTP client to attach the user's github.com or enterprise token to requests bound for third-party TUF mirrors and CDN hosts during gh attestation, gh release verify, and gh release verify-asset operations. Flawed host normalization collapses tuf-repo.github.com (a GitHub Pages site, not an API endpoint) to github.com and falls back to the enterprise token for unrecognized hosts such as tuf-repo-cdn.sigstore.dev and tmaproduction.blob.core.windows.net. Rated CVSS 9.1 by the vendor, but EPSS is only 0.04% (12th percentile) with no public exploit identified at time of analysis and CISA SSVC marking exploitation as none.

Technical ContextAI

GitHub CLI is a widely deployed Go-based command-line tool (package pkg:go/github.com/cli/cli/v2) for interacting with GitHub. The attestation and release-verification subcommands implement Sigstore/TUF (The Update Framework) trust workflows, fetching signed TUF metadata and artifact bundles from external hosts (tuf-repo.github.com, tuf-repo-cdn.sigstore.dev, and Azure Blob Storage at tmaproduction.blob.core.windows.net). These fetches reuse the same shared, authenticated HTTP client the CLI uses for the GitHub API. The root cause maps to CWE-863 (Incorrect Authorization): the auth layer's host-detection logic wildcards any *.github.com subdomain to github.com and defaults unknown hosts to GH_ENTERPRISE_TOKEN, so bearer tokens are attributed to and transmitted to hosts that should never receive them. TUF mirrors are designed to serve public signing metadata and require no authentication, so the token adds no function and only creates exposure.

RemediationAI

Vendor-released patch: upgrade gh to 2.93.0 or later, which corrects the host-detection logic so tokens are no longer attached to TUF mirror requests (advisory: https://github.com/cli/cli/security/advisories/GHSA-8xvp-7hj6-mcj9). Because tokens may already have been transmitted, also revoke and rotate any credentials used with the CLI: personal access tokens and the GitHub CLI OAuth authorization, plus any GH_ENTERPRISE_TOKEN/GITHUB_ENTERPRISE_TOKEN values. Then review personal security logs and enterprise audit logs for anomalous actions tied to those tokens. Until upgrade is possible, the practical compensating control is to avoid running gh attestation, gh release verify, and gh release verify-asset (the only affected commands) - note this disables local artifact/attestation verification, so verification should be performed on a patched host instead. Unsetting the enterprise token variables before running those commands limits enterprise-token exposure but breaks enterprise authentication for the session.