cbcvebase.
CVE-2026-5512
published 2026-04-21

CVE-2026-5512: An improper authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated attacker to determine the names of private…

PriorityP425medium4.3CVSS 3.1
AVNACLPRLUINSUCLINAN
EPSS
0.30%
21.2th percentile
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.

Affected

14 ranges
VendorProductVersion rangeFixed in
githubenterprise_server< 3.14.263.14.26
githubenterprise_server
githubenterprise_server3.14.0 – 3.14.25
githubenterprise_server>= 3.15.0 < 3.15.213.15.21
githubenterprise_server3.15.0 – 3.15.20
githubenterprise_server>= 3.16.0 < 3.16.173.16.17
githubenterprise_server3.16.0 – 3.16.16
githubenterprise_server>= 3.17.0 < 3.17.143.17.14
githubenterprise_server3.17.0 – 3.17.13
githubenterprise_server>= 3.18.0 < 3.18.83.18.8
githubenterprise_server3.18.0 – 3.18.7
githubenterprise_server>= 3.19.0 < 3.19.53.19.5
githubenterprise_server3.19.0 – 3.19.4
githubenterprise_server>= 3.20.0 < 3.20.13.20.1

CVSS provenance

nvdv3.14.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
nvdv4.05.3MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.