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CVE-2020-8929
Ciphertext integrity weakness in Tink
Medium5.3EPSS 0.46%
- Published
- Updated
- Reserved
- Assigned by
Description
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GoogleCNA (assigner) | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
| NVDNVD · Analyzed | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.46% · top 60% of all CVEs (6 Nov 2026)
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The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Weakness
Affected products
- affected stable – < 1.5
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavencom.google.crypto.tink:tinkGHSA-g5vf-v6wf-7w2r (opens in a new tab)
References (2)
- https://github.com/google/tink/commit/93d839a5865b9d950dffdc9d0bc99b71280a8899 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/google/tink/security/advisories/GHSA-g5vf-v6wf-7w2r (opens in a new tab)x_refsource_CONFIRMx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-g5vf-v6wf-7w2r (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2020-8929)Record last updated .