How severe is CVE-2026-5512?

CVE-2026-5512 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-5512 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-5512?

CVE-2026-5512 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-2026-5512?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-5512 have an EU (EUVD) identifier?

Yes. CVE-2026-5512 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-24550.

When was CVE-2026-5512 published?

CVE-2026-5512 was published on 2026-04-21 and last updated on 2026-06-17.

CVE-2026-5512

CVE-2026-5512 is a medium-severity vulnerability in Github Enterprise Server with a CVSS 3.x base score of 4.3. 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-201.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v4: 5.3
EPSS exploit prediction: 0% (21st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-24550
Weakness: CWE-201
Affected product: Github Enterprise Server
Published: 2026-04-21
Last modified: 2026-06-17

Description

An improper authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated attacker to determine the names of private repositories by their numeric ID. The mobile upload policy API endpoint did not perform an early authorization check, and validation error messages included the full repository name for repositories the caller did not have access to. 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-2026-5512?: An improper authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated attacker to determine the names of private repositories by their numeric ID. The mobile upload policy API endpoint did not perform an early authorization check, and validation error messages included the full repository name for repositories the caller did not have access to. 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-2026-5512?: CVE-2026-5512 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-5512 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-5512?: CVE-2026-5512 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-2026-5512?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-5512 have an EU (EUVD) identifier?: Yes. CVE-2026-5512 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-24550.
When was CVE-2026-5512 published?: CVE-2026-5512 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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