Bug 2453160 (CVE-2026-21713)

Summary: CVE-2026-21713 Node.js: Node.js: Information disclosure via timing oracle in HMAC verification
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: caswilli, kaycoth, rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in Node.js. The HMAC (Hash-based Message Authentication Code) verification process uses a comparison method that does not take a constant amount of time. This non-constant-time comparison can leak timing information, which, under specific conditions where precise timing measurements are possible, could be exploited by a remote attacker. This allows the attacker to infer sensitive HMAC values, leading to information disclosure.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2453570, 2453571, 2453572    
Bug Blocks:    

Description OSIDB Bzimport 2026-03-30 20:02:26 UTC 
A flaw in Node.js HMAC verification uses a non-constant-time comparison when validating user-provided signatures, potentially leaking timing information proportional to the number of matching bytes. Under certain threat models where high-resolution timing measurements are possible, this behavior could be exploited as a timing oracle to infer HMAC values.

Node.js already provides timing-safe comparison primitives used elsewhere in the codebase, indicating this is an oversight rather than an intentional design decision.

This vulnerability affects **20.x, 22.x, 24.x, and 25.x**.
Comment 2 errata-xmlrpc 2026-04-09 20:20:35 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:7350 https://access.redhat.com/errata/RHSA-2026:7350
Comment 3 errata-xmlrpc 2026-04-13 02:23:21 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:7675 https://access.redhat.com/errata/RHSA-2026:7675
Comment 4 errata-xmlrpc 2026-04-13 02:47:51 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:7670 https://access.redhat.com/errata/RHSA-2026:7670