CVE Catalog

CVE-2026-15432

HighCVSS 8.2
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.19%

8th percentile - higher than 8% of all known CVEs

Summary

When verifying a MAC with a ChunkedMacVerification object in the Tink library, the tag comparison is not constant-time. This potentially allows an attacker to use timing information as a side channel to determine how many bytes of a given tag match the correct tag, which could lead to bytewise recovery of the correct tag.

Risk Assessment

Risk of recovering the correct MAC tag by an attacker with timing measurements, potentially leading to forgery of authenticated messages.

Recommendation

Update the Tink library to a version where tag comparison is constant-time.

Related vulnerabilities

Original NVD description (English source)

When verifying a mac with a ChunkedMacVerification object, Tink compares the resulting tag with non constant time comparison. This potentially allows an attacker to use timinig information as a side channel in order to get information how many bytes of a given tag match the correct tag. This in turn could allow to find a correct tag bytewise.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS