CVE-2026-5845: An improper authorization vulnerability in scoped user-to-server (ghu_) token authorization in GitHub Enterpri

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CRITICAL 9.6UPGRADE

CVE-2026-5845 is a critical-severity flaw (CVSS 9.6) affecting enterprise server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An improper authorization vulnerability in scoped user-to-server (ghu_) token authorization in GitHub Enterprise Server allows an authenticated attacker to access private repositories outside the intended installation scope, which can include write operations, via an authorization fallback that treated a revoked/deleted installation as a global installation context, which could be chained with token revocation timing and SSH push attribution to o

Why this priority

Critical severity

A fixed release or distro patch exists.

Risk facts

CVSS score	9.6 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 79%)
CISA exploited list	No
Weakness	CWE-639
Published	2026-04-21
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc. (Products Only) · Vendor: github

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-21 23:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

github enterprise server UPGRADE

Affected: < 3.14.26 · >= 3.15.0 and < 3.15.21 · >= 3.16.0 and < 3.16.17 · >= 3.17.0 and < 3.17.14 · >= 3.18.0 and < 3.18.8 · >= 3.19.0 and < 3.19.5 · 3.20.0

Fixed in: 3.14.26, 3.15.21, 3.16.17, 3.17.14, 3.18.8, 3.19.5

Safe to downgrade to: a release before 3.15.0

1. Check installed version

apt-cache policy enterprise-server || rpm -q enterprise-server || enterprise-server --version

2. UPGRADE to 3.14.26 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade enterprise-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade enterprise-server

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.15.0 (Debian / Ubuntu)

apt-cache madison enterprise-server sudo apt install enterprise-server=<VERSION_BEFORE_3.15.0> sudo apt-mark hold enterprise-server

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list enterprise-server sudo dnf downgrade enterprise-server-<VERSION_BEFORE_3.15.0> sudo dnf versionlock add enterprise-server

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-5845?

enterprise server: upgrade to 3.14.26, 3.15.21, 3.16.17, 3.17.14, 3.18.8, 3.19.5. Exact commands for each OS are on this page.

Is CVE-2026-5845 being exploited?

CVE-2026-5845 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-5845 affect?

CVE-2026-5845 affects enterprise server. Severity is critical (CVSS 9.6). An improper authorization vulnerability in scoped user-to-server (ghu_) token authorization in GitHub Enterprise Server allows an authenticated attacker to access private repositories outside the intended installation scope, which can inclu

How urgent is CVE-2026-5845?

Priority 39/100. Critical severity

Software pages

GitHub vulnerabilities

Related CVEs

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CVE-2026-8034 CRITICAL 9.8 UPGRADE A server-side request forgery (SSRF) vulnerability was identified in the GitHub Enterprise Server notebook vie

References

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