Input-Validation Flaw in Tink-go Affects Keyset Integrity
CVE-2026-109425

6.9MEDIUM

Key Information:

Vendor

Tink-crypto

Status
Tink-go
Vendor
CVE Published:
12 October 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-109425?

Tink-go through version 2.8.0 contains an input-validation vulnerability that allows attackers to bypass structural validation checks when creating a keyset handle. Specifically, methods like keyset.NewHandleWithNoSecrets() and ReadWithNoSecrets() skip the crucial Validate() step, thereby permitting malformed public or no-secret keysets that violate Tink's keyset invariants. This flaw can lead to the acceptance of keysets with enabled public keys missing a valid primary key or a DESTROYED key lacking KeyData. As a result, applications relying on successful handle construction may unknowingly process these invalid keysets, leading to inconsistent downstream validations that compromise overall security.

Affected Version(s)

tink-go 2.0.0 <= 2.8.0

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-109425 - Proof of Concept

References

https://github.com/tink-crypto/tink-go/issues/68
technical-descriptionexploit
https://www.vulncheck.com/advisories/tink-go-keyset-valid...
third-party-advisory

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

CayCon
.