CVE-2026-18503
Super-linear CPU usage for unbounded input to csv.Sniffer.sniff()
- State
- Published
- Severity
- 2.4 Low
- Published
- Aug 10, 2026
- Updated
- Oct 14, 2026
- Reserved
- Jul 31, 2026
Description
Attacker-controlled CSV samples can trigger super-linear regular-expression work during dialect sniffing and consume significant CPU when applications pass unbounded input to csv.Sniffer.sniff().
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 2.4 Low | CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N | PSF |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
CPythonPython Software Foundation |
|
References
- https://mail.python.org/archives/list/security-announce@python.org/thread/KQ7NBMCPAZJHRROQXJQE4GMXGLD5KHBS/vendor-advisory
- https://github.com/python/cpython/pull/153694patch
- https://github.com/python/cpython/issues/98820issue-tracking
- https://github.com/python/cpython/commit/063d4555c94ef412c731527dbf30193327f2ee82patch
- https://github.com/python/cpython/commit/476fb09cdb0d73e645849d98c610e7e5697ce7c9patch
- https://github.com/python/cpython/commit/89f29c760c02774b099ddd6863268eb13fa3946apatch
- https://github.com/python/cpython/commit/b30c7fa9edd921a118f286e9f90f560777fa693bpatch
- https://github.com/python/cpython/commit/b09a67a20c464f8288c9f9a6b9c7082a74560024patch
- https://github.com/python/cpython/commit/fd78b565d7c326f96ae903ab945b47f35d829cf4patch
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