CVE-2026-18503CWE-1176

CVE-2026-18503

published August 10, 2026

CVSS
2.4
EPSS
0%
Percentile
2.0
In the wild
Unconfirmed
What it is

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().

The record
Technical detail
CVSS
2.4 · NONE
CVSS v4.0
Not supplied
EPSS
0.00119 · 2.0th percentile
Weakness
CWE-1176 · Inefficient CPU Computation
Published
2026-08-10T18:17Z
References (9)
https://github.com/python/cpython/commit/063d4555c94ef412c731527dbf30193327f2ee82 · [email protected]https://github.com/python/cpython/commit/476fb09cdb0d73e645849d98c610e7e5697ce7c9 · [email protected]https://github.com/python/cpython/commit/89f29c760c02774b099ddd6863268eb13fa3946a · [email protected]https://github.com/python/cpython/commit/b09a67a20c464f8288c9f9a6b9c7082a74560024 · [email protected]https://github.com/python/cpython/commit/b30c7fa9edd921a118f286e9f90f560777fa693b · [email protected]https://github.com/python/cpython/commit/fd78b565d7c326f96ae903ab945b47f35d829cf4 · [email protected]https://github.com/python/cpython/issues/98820 · [email protected]https://github.com/python/cpython/pull/153694 · [email protected]https://mail.python.org/archives/list/[email protected]/thread/KQ7NBMCPAZJHRROQXJQE4GMXGLD5KHBS/ · [email protected]
EPSS history
Timeline
  • 10 AUG 13:45Z
    Super-linear CPU usage for unbounded input to csv.Sniffer.sniff()
    cvelistv5