VulnerabilityAnalyzed

CVE-2026-1355

MEDIUM 6.0EPSS 0.39%

Does this matter?

Lower severity and a low EPSS score (0.39%). Track it; it rarely justifies an emergency change on its own.

Description

A Missing Authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to upload unauthorized content to another user’s repository migration export due to a missing authorization check in the repository migration upload endpoint. By supplying the migration identifier, an attacker could overwrite or replace a victim’s migration archive, potentially causing victims to download attacker-controlled repository data during migration restores or automated imports. An attacker would require authentication to the victim's GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.20 and was fixed in versions 3.19.2, 3.18.5, 3.17.11, 3.16.14, 3.15.18, 3.14.23. This vulnerability was reported via the GitHub Bug Bounty program.

CVSS 4.0: 6.0 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.39% probability · 33th percentile
CISA KEV: Not listed
Weakness: CWE-862
Affected: github/enterprise server
Source: product-cna@github.com

References

https://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.23Product, Release Notes
https://docs.github.com/en/enterprise-server@3.15/admin/release-notes#3.15.18Product, Release Notes
https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.14Product, Release Notes
https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.11Product, Release Notes
https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.5Product, Release Notes
https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.2Product, Release Notes

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.