CVE-2026-1355Missing Authorization Check in GitHub Enterprise Server Allows Unauthorized Uploads to Repository Migration Exports
- 6.0MediumCVSS base score
- 0.45%Exploitation in 30 daysEPSS · top 60% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By GitHub_P
- 27 days later
· 27 days later
Published
- 2 days later
· 2 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_PCNA (assigner) | 4.0 | Medium6.0 | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:L |
| NVDNVD · Analyzed | 4.0 | Medium6.0 | CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.45% · top 60% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.0.
Affected products
- affected 3.19.0 – ≤ 3.19.1
- affected 3.18.0 – ≤ 3.18.4
- affected 3.17.0 – ≤ 3.17.10
- affected 3.16.0 – ≤ 3.16.13
- affected 3.15.0 – ≤ 3.15.17
- affected 3.14.0 – ≤ 3.14.22
References
References6
- https://docs.github.com/en/[email protected]/admin/release-notes#3.19.2 (opens in a new tab)
- https://docs.github.com/en/[email protected]/admin/release-notes#3.18.5 (opens in a new tab)
- https://docs.github.com/en/[email protected]/admin/release-notes#3.17.11 (opens in a new tab)
- https://docs.github.com/en/[email protected]/admin/release-notes#3.16.14 (opens in a new tab)
- https://docs.github.com/en/[email protected]/admin/release-notes#3.15.18 (opens in a new tab)
- https://docs.github.com/en/[email protected]/admin/release-notes#3.14.23 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-8392 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-1355)Record last updated .