CVE-2026-1355

mediumpriority · track · 26OT risk · elevatedEPSS 0.005 · 39 %ileDEEUNLUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.46% (39th) EPSS
CVSS 6.5 · medium
Is it mine?
20 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · cert_bund · ncsc_nl

EPSS · scored 2026-10-27

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.

01

cvss

Technical severity, 0–10. One row per scoring source.

6.5
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 2.3–6.5

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:Nprimary · NVD / NIST USexploitability 2.8 · impact 3.6
v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:Nsecondary · NCSC-NL NL
v4.06mediumCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:Lsecondary · ENISA EU
v4.06mediumCVSS: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:Xsecondary · product-cna@github.com
v4.02.3lowCVSS: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:U/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:Xsecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-862USCWE-862US
04

affected products (20)

Products and version ranges known to be affected.

05

advisories (2)

Vendor and ecosystem advisories describing this.

  • NCSC-2026-0067Kwetsbaarheden verholpen in GitHub Enterprise ServerNL2026-02-20csaf · ncsc_nlNL

    GitHub heeft kwetsbaarheden verholpen in GitHub Enterprise Server (Specifiek voor versies vóór 3.20, 3.19.2, 3.18.5 en 3.17.11).

  • WID-SEC-W-2026-0460Microsoft GitHub Enterprise Server: Mehrere Schwachstellen ermöglichen Umgehen von SicherheitsvorkehrungenDeutsch2026-02-18csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Microsoft GitHub Enterprise Server ausnutzen, um Sicherheitsvorkehrungen zu umgehen.

06

also known as (3)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdcert_bundncsc_nlnvdNVDCVE.orgMITRE
published 2026-02-18modified 2026-06-17
08

references (18)

External citations — patches, advisories, analysis.

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