CVE-2026-124539: JSON-XS (Perl module) · Memory Leak
Affects JSON-XS (Perl module)Source CVE Database V5
Not known to be exploited : upgrade to 4.05 when convenient.
Data as of 14 Nov 2026, 12:17 UTC
Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD
Thin evidence
One scorer or none- Patch
- Available – fixed in 4.05
Exploitation evidence
Disclosed: evidence found.
CVE published 14 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 14 Nov 2026.
What to do
Upgrade JSON-XS (Perl module) to 4.05.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| JSON-XS | Affected
| Fixed in
|
CPANJSON-XSpkg:cpan/JSON-XSOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade JSON::XS to version 4.05 or later, where the memory leak is fixed. No other mitigations are indicated.
Description
CVE-2026-124539 is a memory leak vulnerability in JSON::XS for Perl versions before 4.05. The flaw occurs when decoding an object with a missing colon after a key, causing the decoded key scalar to not be freed. This results in a memory leak where each rejected document retains one key in memory, potentially exhausting process memory over time.