CVE-2026-18503 (GCVE-0-2026-18503)

Vulnerability from cvelistv5 – Published: 2026-08-10 13:45 – Updated: 2026-08-13 00:28
VLAI
Title
Super-linear CPU usage for unbounded input to csv.Sniffer.sniff()
Summary
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().
Severity
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
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-10 17:56 UTC
CWE
Assigner
References
Impacted products
Vendor Product Version CPE status
Python Software Foundation CPython Affected: 0 , < 3.10.21 (python)
Affected: 3.11.0 , < 3.11.16 (python)
Affected: 3.12.0 , < 3.12.14 (python)
Affected: 3.13.0 , < 3.13.15 (python)
Affected: 3.14.0 , < 3.14.7 (python)
Affected: 3.15.0a1 , < 3.15.0rc1 (python)
guessed Create a notification for this product.
Credits
Serhiy Storchaka (https://github.com/serhiy-storchaka) Jack Desert (https://github.com/jackdesert) Sean Gilligan (https://github.com/sg3-141-592) Seth Larson (https://github.com/sethmlarson)
Show details on NVD website
To clipboard 

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.