An unhandled exception vulnerability exists during Google Sign-In with Google API C++…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA.
Summary
An unhandled exception vulnerability exists during Google Sign-In with Google API C++ Client before 2019-04-10. It potentially causes an outage of third-party services that were not designed to recover from exceptions. On the client, ID token handling can cause an unhandled exception because of misinterpretation of an integer as a string, resulting in denial-of-service and then other users can no longer login/sign-in to the affected third-party service. Once this third-party service uses Google Sign-In with google-api-cpp-client, a malicious user can trigger this client/auth/oauth2_authorization.cc vulnerability by requesting the client to receive the ID token from a Google authentication server.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2018-20840
- 2026-10-03 Alias added: GHSA-jw9r-r4mj-mpxx
- 2026-10-14 EPSS moved to the 50th–90th percentile
References
Sources
- CVE-2018-20840 · CVE Program
- CVE-2018-20840 · NVD
- FIRST EPSS
- GHSA-jw9r-r4mj-mpxx · GitHub Advisory Database · CC BY 4.0
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