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Incorrect Calculation of Buffer Size The advisory has been revoked - it doesn't affect any version of package rhcos  (opens in a new tab)

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EPSS
0.78% (54th percentile)

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  • Snyk IDSNYK-RHEL10-RHCOS-16785402
  • published21 May 2026
  • disclosed20 May 2026
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Introduced: 20 May 2026

CVE-2026-42944  (opens in a new tab)
CWE-131  (opens in a new tab)

Amendment

The Red Hat security team deemed this advisory irrelevant for RHEL:10.

NVD Description

Note: Versions mentioned in the description apply only to the upstream rhcos package and not the rhcos package as distributed by RHEL.

NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a vulnerability that results in heap overflow when encoding multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options in the reply packet. The relevant options ('nsid', 'answer-cookie', 'pad-responses' (default)) need to be enabled for the vulnerability to be exploited. An adversary who can query Unbound can exploit the vulnerability by attaching multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options to the query. A flaw in the size calculation of the EDNS field truncates the correct value which allows the encoder to overflow the available space when writing. Those two combined lead to a heap overflow write of Unbound controlled data and eventually a crash. Unbound 1.25.1 contains a patch with a fix to de-duplicate the EDNS options and a fix to prevent truncation of the EDNS field size calculation.