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TI-2020-07166 Aliases CVE-2020-8929GHSA-g5vf-v6wf-7w2r

Ciphertext integrity weakness in Tink

Priority LOW 24CWE-176Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
None · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-327.

Summary

A mis-handling of invalid unicode characters in the Java implementation of Tink versions prior to 1.5 allows an attacker to change the ID part of a ciphertext, which result in the creation of a second ciphertext that can decrypt to the same plaintext. This can be a problem with encrypting deterministic AEAD with a single key, and rely on a unique ciphertext-per-plaintext.

Why it matters now

EPSS 0.00463 40th percentileScored 2026-11-07
Fix Fixed Tink (Google LLC): 1.5com.google.crypto.tink:tink (Maven): 1.5.0

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
GoogleTinkstable to before 1.51.5Patch availableCNA
—com.google.crypto.tink:tink (Maven)before 1.5.01.5.0Patch availableGHSA-g5vf-v6wf-7w2r
  • Tink VendorGoogle Affected stable to before 1.5 Fixed in 1.5 Patch available CNA
  • com.google.crypto.tink:tink (Maven) Vendor— Affected before 1.5.0 Fixed in 1.5.0 Patch available GHSA-g5vf-v6wf-7w2r

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:google:tink_java:*:*:*:*:*:*:*:*before 1.5.0VulnerableGoogle
  • cpe:2.3:a:google:tink_java:*:*:*:*:*:*:*:* Versions before 1.5.0 Vulnerable ·Google

Remediation

  • Fix · CNA Tink (Google LLC) Fixed in 1.5
  • Fix · GHSA-g5vf-v6wf-7w2r com.google.crypto.tink:tink (Maven) Fixed in 1.5.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2020-8929
  2. 2026-10-03 Alias added: GHSA-g5vf-v6wf-7w2r

References

Patch 2

Advisory 1

Other 1

  • TI-2026-12987 Observable Timing Discrepancy in Tink-Java and Tink-Android ChunkedMacVerification CVSS 4.0HIGH 8.2

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences