CVE-2026-124539
JSON::XS versions before 4.05 for Perl leak the decoded key of an object rejected for a missing colon in decode_hv
Description
JSON::XS versions before 4.05 for Perl leak the decoded key of an object rejected for a missing colon in decode_hv. Unless it is short plain ASCII, a quoted key is decoded into a new scalar. Nothing frees that scalar when the object is rejected for a missing ':' after the key. A process that keeps running after a failed decode retains one key per rejected document, with its size chosen by the sender. Repeated requests exhaust process memory.
INFO
Published Date :
Nov. 14, 2026, 12:17 p.m.
Last Modified :
Nov. 14, 2026, 12:17 p.m.
Remotely Exploit :
No
Source :
9b29abf9-4ab0-4765-b253-1875cd9b441e
Affected Products
The following products are affected by CVE-2026-124539
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update JSON::XS to version 4.05 or later.
- Monitor memory usage for affected processes.
- Consider restarting long-running processes.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-124539.
| URL | Resource |
|---|---|
| https://metacpan.org/release/MLEHMANN/JSON-XS-4.05/changes |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-124539 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-124539
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-124539 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-124539 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 9b29abf9-4ab0-4765-b253-1875cd9b441e
Nov. 14, 2026
Action Type Old Value New Value Added Description JSON::XS versions before 4.05 for Perl leak the decoded key of an object rejected for a missing colon in decode_hv. Unless it is short plain ASCII, a quoted key is decoded into a new scalar. Nothing frees that scalar when the object is rejected for a missing ':' after the key. A process that keeps running after a failed decode retains one key per rejected document, with its size chosen by the sender. Repeated requests exhaust process memory. Added CWE CWE-401 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/124xxx/CVE-2026-124539.json">CVE-2026-124539</a> Added Reference https://metacpan.org/release/MLEHMANN/JSON-XS-4.05/changes