How severe is CVE-2026-5845?

CVE-2026-5845 has a CVSS 3.x base score of 9.6, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-5845 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-5845?

CVE-2026-5845 primarily affects Github Enterprise Server. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-5845?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-5845 have an EU (EUVD) identifier?

Yes. CVE-2026-5845 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-24552.

When was CVE-2026-5845 published?

CVE-2026-5845 was published on 2026-04-21 and last updated on 2026-06-17.

CVE-2026-5845

CVE-2026-5845 is a critical-severity vulnerability in Github Enterprise Server with a CVSS 3.x base score of 9.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-639.

Key facts

Severity: Critical (CVSS 3.x base score 9.6)
CVSS v4: 7.2
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-24552
Weakness: CWE-639
Affected product: Github Enterprise Server
Published: 2026-04-21
Last modified: 2026-06-17

Description

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 obtain and reuse a victim-scoped token. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.1, 3.19.5, 3.18.8, 3.17.14, 3.16.17, 3.15.21, and 3.14.26. This vulnerability was reported via the GitHub Bug Bounty program.

Frequently asked questions

What is CVE-2026-5845?: 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 obtain and reuse a victim-scoped token. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.1, 3.19.5, 3.18.8, 3.17.14, 3.16.17, 3.15.21, and 3.14.26. This vulnerability was reported via the GitHub Bug Bounty program.
How severe is CVE-2026-5845?: CVE-2026-5845 has a CVSS 3.x base score of 9.6, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-5845 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-5845?: CVE-2026-5845 primarily affects Github Enterprise Server. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-5845?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-5845 have an EU (EUVD) identifier?: Yes. CVE-2026-5845 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-24552.
When was CVE-2026-5845 published?: CVE-2026-5845 was published on 2026-04-21 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
cpe:2.3:a:github:enterprise_server:3.20.0:*:*:*:*:*:*:*

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