Medium 6.0Published Feb 18, 2026

CVE-2026-1355Missing Authorization Check in GitHub Enterprise Server Allows Unauthorized Uploads to Repository Migration Exports

Updated under an hour ago (Oct 26, 2026, 2:00 PM ET)

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It affects GitHub Enterprise Server. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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: 6.0 MEDIUM (v4.0, CNA)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
Weakness (CWE): CWE-862
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_P
NVD analysis: Analyzed
Record last updated: Feb 20, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

GitHub Enterprise Server github:enterprise_server (from the name)	from 3.19.0 through 3.19.1; fixed at 3.19.2; from 3.18.0 through 3.18.4; fixed at 3.18.5; from 3.17.0 through 3.17.10; fixed at 3.17.11; from 3.16.0 through 3.16.13; fixed at 3.16.14; from 3.15.0 through 3.15.17; fixed at 3.15.18; from 3.14.0 through 3.14.22; fixed at 3.14.23	CNA record
github enterprise_server github:enterprise_server	before 3.14.23; from 3.15.0 before 3.15.18; from 3.16.0 before 3.16.14; from 3.17.0 before 3.17.11; from 3.18.0 before 3.18.5; from 3.19.0 before 3.19.2	NVD

References

References

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

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.