Answer in brief
CVE-2026-124541 records a Unknown severity vulnerability in JSON::XS versions before 4.05 for Perl leak the decoded part of a rejected long string in decode_str. The current sources do not mark it as known exploited. The current feed maps JSON-XS (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps JSON-XS (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| JSON-XSgeneric | >=0 <4.05 | 4.05 |
Published upstream
Nov 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 14, 2026
JSON::XS versions before 4.05 for Perl leak the decoded part of a rejected long string in decode_str. A string is decoded through a fixed-size buffer (16 KiB in 4.04), and each time the buffer fills its contents move into a new scalar. Nothing frees that scalar when the string is then rejected for a control character, an invalid escape, malformed UTF-8 or the end of the input. A process that keeps running after a failed decode retains the decoded part of each rejected string, with its size chosen by the sender. Repeated requests exhaust process memory.
Quoted source text, attributed separately from HOL analysis.