Is there a public exploit for CVE-2026-129114?

No public exploit for CVE-2026-129114 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

— Unscored

JSON::XS versions from 3.04 before 4.05 for Perl write one byte past a heap buffer when appending a one-byte chunk in incrparse.

CVE-2026-129114

JSON::XS versions from 3.04 before 4.05 for Perl write one byte past a heap buffer when appending a one-byte chunk in incrparse. The incremental buffer grows to one and a half times the length it must hold, with no room reserved for the terminating NUL. For an empty buffer and a one-byte chunk that request is one byte, which a buffer whose front was removed by earlier decodes can already have, so nothing is reallocated and the NUL lands one byte past the allocation. A peer streaming data to an incrparse consumer, choosing how the input is split into reads, can cause a one-byte heap out-of-bounds write.

Assessment

CVSS: Not yet scored
Severity: Unscored
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 14 November 2026
Last updated: 14 November 2026
Assigner: CPANSec

At the source

EUVD (ENISA)

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