# CVE-2026-104608: Use-after-free vulnerability in GitHub Enterprise Server allowed remote code execution in the Git service

Status: published. Published: 2026-11-03. Updated: 2026-11-03.

A remote code execution vulnerability was identified in GitHub Enterprise Server in the Git service (babeld). babeld held references into internal collections while calling into the SSH library, where a re-entrant callback could modify a collection and invalidate those references. An attacker with an account and SSH access to the instance could leverage this use-after-free into a controlled write and run arbitrary commands as babeld, including disclosure of its environment secrets. Exploitation required per-build memory offsets; failed attempts crashed babeld. This affected all releases prior to 3.23 and was fixed in 3.22.3, 3.21.8, 3.20.10, and 3.19.14. This vulnerability was reported via the GitHub Bug Bounty program.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- GitHub / Enterprise Server: ≥ 3.19.0; < 3.19.* (affected, semver); unaffected at 3.19.14; ≥ 3.20.0; < 3.20.* (affected, semver); unaffected at 3.20.10; ≥ 3.21.0; < 3.21.* (affected, semver); unaffected at 3.21.8; ≥ 3.22.0; < 3.22.* (affected, semver); unaffected at 3.22.3. Source: CNA: GitHub_P

## Severity and prioritization

- CVSS 4.0: 7.7 (high); CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:L/SI:N/SA:N; source: CNA: GitHub_P

- CVSS 4.0: 7.7 (high); CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:L/SI:N/SA:N/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; source: NVD: product-cna@github.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-416, CWE-1265

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.14 (CNA: GitHub_P; release-notes)

- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.10 (CNA: GitHub_P; release-notes)

- https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.8 (CNA: GitHub_P; release-notes)

- https://docs.github.com/en/enterprise-server@3.22/admin/release-notes#3.22.3 (CNA: GitHub_P; release-notes)

- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.14 (product-cna@github.com)

- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.10 (product-cna@github.com)

- https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.8 (product-cna@github.com)

- https://docs.github.com/en/enterprise-server@3.22/admin/release-notes#3.22.3 (product-cna@github.com)

## Provenance

- CNA: GitHub_P: https://www.cve.org/CVERecord?id=CVE-2026-104608; retrieved 2026-11-03; source updated 2026-11-03

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-104608; retrieved 2026-11-04; source updated 2026-11-03

Revision: 7730da5b89ee1206ac77983e001a531adffce71e9958698eae998b8f5e6f86ef

Canonical: https://y2.dev/cve/CVE-2026-104608

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