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 incr_parse
Summary
| CVE | CVE-2026-129114 |
|---|---|
| State | PUBLISHED |
| Assigner | CPANSec |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-11-14 12:17:44 UTC |
| Updated | 2026-11-14 12:17:44 UTC |
| Description | 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 incr_parse. 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 incr_parse consumer, choosing how the input is split into reads, can cause a one-byte heap out-of-bounds write. |
Risk And Classification
Problem Types: CWE-122 | CWE-193 | CWE-193 CWE-193 Off-by-one Error | CWE-122 CWE-122 Heap-based Buffer Overflow
There are no known software configurations currently associated with this CVE in NVD or the CVE Program record.
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| metacpan.org/release/MLEHMANN/JSON-XS-4.05/changes | 9b29abf9-4ab0-4765-b253-1875cd9b441e | metacpan.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Albert Gierlach (rivit) (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-11-13T00:00:00.000Z | Version 4.05 released with fix. |
Solutions
CNA: Upgrade to JSON-XS 4.05 or later.
There are currently no legacy QID mappings associated with this CVE.