CVE catalog

CVE-2026-18503

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().

[CVE catalog]

Severity: Low · CVSS 3.3CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
Published: Aug 10, 2026, 1:45:31 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.12% · Oct 22, 2026

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().

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	pypy3	sid	`8.0.1+dfsg-1`	vulnerable
Debian	pypy3	forky	`8.0.1+dfsg-1`	vulnerable
Debian	pypy3	trixie	`7.3.19+dfsg-2`	vulnerable
Debian	pypy3	bookworm	`7.3.11+dfsg-2+deb12u3`	vulnerable
Debian	python3.11	bookworm	`3.11.2-6+deb12u8`	vulnerable
Debian	python3.11	bookworm-security	`3.11.2-6+deb12u9`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	pypy3	source	sid	`(unfixed)`	not yet assigned	Not reported	[1147450]
Debian	pypy3	source	forky	`(unfixed)`	not yet assigned	Not reported	[1147450]
Debian	pypy3	source	trixie	`(unfixed)`	not yet assigned	Not reported	[1147450]
Debian	pypy3	source	bookworm	`(unfixed)`	not yet assigned	Not reported	[1147450]
Debian	python3.11	source	bookworm	`3.11.2-6+deb12u9`	not yet assigned	Not reported	Not reported

[Debian bug #1147450]

Notes

[trixie] pypy3: Minor issue [bookworm] pypy3: Minor issue

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[idle-python3.11]Affected
Source package: [python3.11]
Details (4)
- 3.11.2-6+deb12u8 · all · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u8 · all · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · all · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · all · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
[libpython3.11]Affected
Source package: [python3.11]
Details (4)
- 3.11.2-6+deb12u8 · amd64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u8 · arm64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · amd64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · arm64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
[libpython3.11-dbg]Affected
Source package: [python3.11]
Details (4)
- 3.11.2-6+deb12u8 · amd64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u8 · arm64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · amd64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · arm64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
[libpython3.11-dev]Affected
Source package: [python3.11]
Details (4)
- 3.11.2-6+deb12u8 · amd64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u8 · arm64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · amd64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · arm64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
[libpython3.11-minimal]Affected
Source package: [python3.11]
Details (4)
- 3.11.2-6+deb12u8 · amd64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u8 · arm64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · amd64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · arm64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
[libpython3.11-stdlib]Affected
Source package: [python3.11]
Details (4)
- 3.11.2-6+deb12u8 · amd64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u8 · arm64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · amd64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · arm64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
[libpython3.11-testsuite]Affected
Source package: [python3.11]
Details (4)
- 3.11.2-6+deb12u8 · all · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u8 · all · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · all · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · all · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
[pypy3]Affected
Details (2)
- 7.3.11+dfsg-2+deb12u3 · amd64 · bookworm
  Affected
  nvd · pypy3 · debian · bookworm
- 7.3.11+dfsg-2+deb12u3 · arm64 · bookworm
  Affected
  nvd · pypy3 · debian · bookworm
[pypy3-dev]Affected
Source package: [pypy3]
Details (2)
- 7.3.11+dfsg-2+deb12u3 · all · bookworm
  Affected
  nvd · pypy3 · debian · bookworm
- 7.3.11+dfsg-2+deb12u3 · all · bookworm
  Affected
  nvd · pypy3 · debian · bookworm
[pypy3-doc]Affected
Source package: [pypy3]
Details (2)
- 7.3.11+dfsg-2+deb12u3 · all · bookworm
  Affected
  nvd · pypy3 · debian · bookworm
- 7.3.11+dfsg-2+deb12u3 · all · bookworm
  Affected
  nvd · pypy3 · debian · bookworm
[pypy3-lib]Affected
Source package: [pypy3]
Details (2)
- 7.3.11+dfsg-2+deb12u3 · amd64 · bookworm
  Affected
  nvd · pypy3 · debian · bookworm
- 7.3.11+dfsg-2+deb12u3 · arm64 · bookworm
  Affected
  nvd · pypy3 · debian · bookworm
[pypy3-lib-testsuite]Affected
Source package: [pypy3]
Details (2)
- 7.3.11+dfsg-2+deb12u3 · all · bookworm
  Affected
  nvd · pypy3 · debian · bookworm
- 7.3.11+dfsg-2+deb12u3 · all · bookworm
  Affected
  nvd · pypy3 · debian · bookworm
[pypy3-tk]Affected
Source package: [pypy3]
Details (2)
- 7.3.11+dfsg-2+deb12u3 · amd64 · bookworm
  Affected
  nvd · pypy3 · debian · bookworm
- 7.3.11+dfsg-2+deb12u3 · arm64 · bookworm
  Affected
  nvd · pypy3 · debian · bookworm
[pypy3-venv]Affected
Source package: [pypy3]
Details (2)
- 7.3.11+dfsg-2+deb12u3 · all · bookworm
  Affected
  nvd · pypy3 · debian · bookworm
- 7.3.11+dfsg-2+deb12u3 · all · bookworm
  Affected
  nvd · pypy3 · debian · bookworm
[python3.11]Affected
Details (4)
- 3.11.2-6+deb12u8 · amd64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u8 · arm64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · amd64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · arm64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
[python3.11-dbg]Affected
Source package: [python3.11]
Details (4)
- 3.11.2-6+deb12u8 · amd64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u8 · arm64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · amd64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · arm64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
[python3.11-dev]Affected
Source package: [python3.11]
Details (4)
- 3.11.2-6+deb12u8 · amd64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u8 · arm64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · amd64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · arm64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
[python3.11-doc]Affected
Source package: [python3.11]
Details (4)
- 3.11.2-6+deb12u8 · all · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u8 · all · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · all · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · all · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
[python3.11-examples]Affected
Source package: [python3.11]
Details (4)
- 3.11.2-6+deb12u8 · all · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u8 · all · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · all · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · all · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
[python3.11-full]Affected
Source package: [python3.11]
Details (4)
- 3.11.2-6+deb12u8 · amd64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u8 · arm64 · bookworm
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · amd64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm
- 3.11.2-6+deb12u3 · arm64 · bookworm-security
  Affected · Fixed: 3.11.2-6+deb12u9
  nvd · python3.11 · debian · bookworm

Next results

Observed: Oct 23, 2026, 9:42:17 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]