CVE-2026-123338 json
Apache DataSketches C++: Out-of-bounds write in REQ sketch deserialization allows memory corruption via a crafted sketch
published 2d ago modified 2d ago also EUVD-2026-125274
- cvss
- —
- not scored
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 13%
- public exploits
- 0
- none known
Summary
Out-of-bounds Write vulnerability in Apache DataSketches C++. An application that deserializes a REQ sketch from an untrusted source can have heap memory corrupted by a crafted sketch, because the serialized compactor headers were not validated.
This issue affects Apache DataSketches C++: from 3.0.0 through 5.3.0.
Users are recommended to upgrade to version 5.3.1, which fixes the issue.
Patch / fix
Is CVE-2026-123338 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-14).
Affected products
- Apache Software Foundation Apache DataSketches C++
Classification
- Weakness
-
- CWE-787 Out-of-bounds Write
References
-
github.com
/apache/datasketches-cpp/commit/9839ffd2ccc038d453e38b545750a5ed2d589dea
patch
-
github.com
/apache/datasketches-cpp/pull/568
patch
-
lists.apache.org
/thread/wjsso4wl0f0nczwh7gd74kc5wckn1635
vendor-advisory
-
github.com
/apache/datasketches-cpp/releases/tag/5.3.1
release-notes
- openwall.com /lists/oss-security/2026/11/13/2
Sources
- CVE List CVE-2026-123338
- NVD CVE-2026-123338
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.