CVE-2026-185032.4LowCWE-1176

CVE-2026-18503: Super-linear CPU usage for unbounded input to csv.Sniffer.sniff()

Python Software Foundation · CPython

Vendor fix available · Affected: Python Software Foundation CPython · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.1%probability of exploitation in the next 30 days

2nd percentile

050100

Higher than 2% of scored CVEs

2.4LowCVSS 4.0

LowMediumHighCrit.

DescriptionCVE.org

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().

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

Python Software Foundation · CPythonbefore 3.10.21; from 3.11.0 before 3.11.16; from 3.12.0 before 3.12.14; from 3.13.0 before 3.13.15; from 3.14.0 before 3.14.7; from 3.15.0a1 before 3.15.0rc1 and 1 more

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Inefficient CPU Computation · Denial of Service
Vendor: Python Software Foundation
Published: August 2026
Band: Unlikely (under 1%), August 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-18503 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.