6.5

CVE-2026-103620: github enterprise_server Missing Authorization

CVSS: 6.5v3.1MediumAnalyzed
Published 06-10-2026Last modified 07-10-2026
Open JSON

Vulnerability summary

CVE-2026-103620 is a medium (CVSS 6.5) Missing Authorization vulnerability in github enterprise_server. EPSS estimates a 0.61% chance of exploitation in the next 30 days, higher than 48.3% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.61%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 06-10-2026
    PublishedVulnerability first disclosed.
  2. 07-10-2026
    Last modifiedVulnerability information updated.

Description

A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed a repository collaborator with write access to delete the current default branch through the GraphQL API and cause an attacker-controlled branch to become the new default. In repositories that required pull-request review but did not restrict branch deletion, this bypassed the review requirement and caused fresh clones and default-branch API requests to use attacker-controlled content. This vulnerability affected supported GitHub Enterprise Server releases in the 3.18, 3.19, 3.20, 3.21, and 3.22 series and was fixed in versions 3.18.16, 3.19.13, 3.20.9, 3.21.7, and 3.22.2. This vulnerability was reported via the GitHub Bug Bounty program.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.61%

Chance of exploitation in the next 30 days

Percentile

48%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

07-10-202620-10-2026
EPSS score
0.61%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Github1 product
  • enterprise_server≥ 3.18.0, < 3.18.* | ≥ 3.19.0, < 3.19.* | ≥ 3.20.0, < 3.20.* | ≥ 3.21.0, < 3.21.* | ≥ 3.22.0, < 3.22.* | ≥ 3.18.0, < 3.18.16 | ≥ 3.19.0, < 3.19.13 | ≥ 3.20.0, < 3.20.9 | ≥ 3.21.0, < 3.21.7 | ≥ 3.22.0, < 3.22.2

1 vendor · 1 product

References

5 links