CVE-2026-124536
JSON::XS versions before 4.05 for Perl allow memory exhaustion by buffering incremental input past max_size after a NUL byte in incr_parse
Description
JSON::XS versions before 4.05 for Perl allow memory exhaustion by buffering incremental input past max_size after a NUL byte in incr_parse. The parser appends each chunk to its buffer and compares max_size with how far it has progressed, not with the buffer length. It treats a NUL byte as the end of the input, so a NUL within the first max_size bytes keeps it short of the limit. The buffer keeps growing, and incr_skip cannot remove the NUL. A peer streaming data to an incr_parse consumer can exhaust process memory regardless of max_size.
Key facts
- Published
- 14 Nov 2026
- Last changed
- 14 Nov 2026
- Assigned by
- CPANSec
- EPSS
- 0.187% likely to be exploited in the next 30 days, higher than 8.34% of CVEs (scores for 15 Nov 2026)
What to do
- Upgrade to JSON-XS 4.05 or later.CNA solution statement
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Timeline
- 13 Nov 2026 Version 4.05 released with fix.
- 14 Nov 2026 Published