CVE-2026-12345
What it is
The cleanup of tempfile.TemporaryDirectory is vulnerable to a race condition. An attacker who can modify the tree during cleanup can replace a directory with a symbolic link, causing files outside of the temporary directory to be deleted or have their permissions and file flags reset, with the privileges of the process performing the cleanup. Note that platforms where shutil.rmtree.avoids_symlink_attacks is false, remain affected, and file flags may still be reset outside of the tree on all platforms.
At a glance
- Exploitability
- Can be exploited locally on the machine without logging in. High risk of data tampering, service disruption.
- Exploit odds
- 0.3% 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: 0.3% in the next 30 days (EPSS).
- Severity: 5.9 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Weakness
- CWE-59
- Record status
- Awaiting Analysis
Attack profile CVSS 4.0 · 5.9
- Attack vector
- Local
- Complexity
- Low
- Attack requirements
- Present
- Privileges needed
- None
- User interaction
- None
- Confidentiality
- None
- Integrity
- High
- Availability
- High
Raw vector
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/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-2026-12345.md and follow it. Check whether this project is affected by CVE-2026-12345. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/python/cpython/commit/0478b52788117db4b831b3efd648f56b777628aa
- https://github.com/python/cpython/commit/06ef3d43fdaf4da97af12fa694b4886092c4b970
- https://github.com/python/cpython/commit/458e7134a5af7f86aee9d21b51cf499b41aa4420
- https://github.com/python/cpython/commit/58ed0259cae509a19138795df302fe60b544dc74
- https://github.com/python/cpython/commit/5c20517a4fc56683efe63a7751020db9573f538d
- https://github.com/python/cpython/commit/c39b52d00b42200aaadff679e2fe3f1006d57c58
- https://github.com/python/cpython/commit/e1f3590f155c6d66007e958c98c9d69316551993
- https://github.com/python/cpython/pull/157580
References
- https://github.com/python/cpython/commit/0478b52788117db4b831b3efd648f56b777628aa
- https://github.com/python/cpython/commit/06ef3d43fdaf4da97af12fa694b4886092c4b970
- https://github.com/python/cpython/commit/458e7134a5af7f86aee9d21b51cf499b41aa4420
- https://github.com/python/cpython/commit/58ed0259cae509a19138795df302fe60b544dc74
- https://github.com/python/cpython/commit/5c20517a4fc56683efe63a7751020db9573f538d
- https://github.com/python/cpython/commit/c39b52d00b42200aaadff679e2fe3f1006d57c58
- https://github.com/python/cpython/commit/e1f3590f155c6d66007e958c98c9d69316551993
- https://github.com/python/cpython/issues/157579
- https://github.com/python/cpython/pull/157580
- http://www.openwall.com/lists/oss-security/2026/09/29/40