CVE-2026-170846.0MediumCWE-436

CVE-2026-17084: stringprep.map_table_b2() deviates from RFC 3454 Table B.2

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.

0.8%probability of exploitation in the next 30 days

55th percentile

050100

Higher than 55% of scored CVEs

6.0MediumCVSS 4.0

LowMediumHighCrit.

DescriptionCVE.org

The "stringprep" module didn't process characters from RFC 3454 tables B.2 or B.3 correctly: the latest Unicode codepoint attributes were used instead of the specified Unicode 3.2.0. This behavior would cause mismatches when processing domain names using IDNA 2003 (the "idna" codec) and the in_table_b2() function of the "stringprep" module. This only affects domain names containing characters that were not previously registered or had their Unicode attributes such as case-folding behavior updated since Unicode 3.2.0.

Affected products1

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

Python Software Foundation · CPythonbefore 3.10.22; from 3.11.0 before 3.11.17; from 3.12.0 before 3.12.15; from 3.13.0 before 3.13.16; from 3.14.0 before 3.14.8; from 3.15.0a1 before 3.15.0rc2

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: Interpretation Conflict · Input Validation and Logic
Vendor: Python Software Foundation
Published: August 2026
Band: Unlikely (under 1%), August 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-17084 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.

References

1 more reference is in the CVE record.