CVE-2026-15343
What it is
A path traversal vulnerability was identified in GitHub Enterprise Server that allowed an attacker with code execution inside a Dependabot updater container to write files to arbitrary repository paths, including GitHub Actions workflow files under .github/workflows/, because path validation did not check the actual write destination. The initial fix in versions 3.21.3, 3.20.5, 3.19.9, 3.18.12, and 3.17.18 was incomplete because validation checked the supplied symlink target, while the publisher wrote the file using its directory and name. Writing GitHub Actions workflow files required the Dependabot installation to have workflows: write permission. Depending on repository permissions and workflow configuration, including a relevant pull_request_target workflow or auto-merge, an injected workflow could execute with access to GitHub Actions secrets. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.23 and was fully fixed in versions 3.22.3, 3.21.8, 3.20.10, and 3.19.14. This vulnerability was reported via the GitHub Bug Bounty program.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering.
- Exploit odds
- 1.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 1.2% in the next 30 days (EPSS).
- Severity: 8.6 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 1.2% · EPSS, next 30 days
- Weakness
- CWE-22 · Path traversal
- Record status
- Deferred
Attack profile CVSS 4.0 · 8.6
- Attack vector
- Network
- Complexity
- Low
- Attack requirements
- None
- Privileges needed
- Low
- User interaction
- None
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/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
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-15343.md and follow it. Check whether this project is affected by CVE-2026-15343. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
References
- https://docs.github.com/en/[email protected]/admin/release-notes#3.17.18
- https://docs.github.com/en/[email protected]/admin/release-notes#3.18.12
- https://docs.github.com/en/[email protected]/admin/release-notes#3.19.14
- https://docs.github.com/en/[email protected]/admin/release-notes#3.19.9
- https://docs.github.com/en/[email protected]/admin/release-notes#3.20.10
- https://docs.github.com/en/[email protected]/admin/release-notes#3.20.5
- https://docs.github.com/en/[email protected]/admin/release-notes#3.21.3
- https://docs.github.com/en/[email protected]/admin/release-notes#3.21.8
- https://docs.github.com/en/[email protected]/admin/release-notes#3.22.3