Reachable assertion in Meta fizz
Priority MEDIUM 40CWE-617Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-617.
Summary
There is a vulnerability in the fizz library prior to v2023.01.30.00 where a CHECK failure can be triggered remotely. This behavior requires the client supported cipher advertisement changing between the original ClientHello and the second ClientHello, crashing the process (impact is limited to denial of service).
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00723 54th percentileScored 2026-11-07
Fix Fixed fizz (Facebook): v2023.01.30.00
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA fizz (Facebook) Fixed in v2023.01.30.00
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2023-23759
- 2026-10-03 Alias added: GHSA-2x3r-3grm-f4ww
References
More Meta Fizz vulnerabilities
- TI-2019-08929 Resource allocation without limits in Meta fizz CVSS 3.0HIGH 7.5
- TI-2019-02625 Infinite loop in Meta fizz CVSS 3.1HIGH 7.5
Sources
- CVE-2023-23759 · CVE Program
- CVE-2023-23759 · NVD
- FIRST EPSS
- GHSA-2x3r-3grm-f4ww · GitHub Advisory Database · CC BY 4.0
- CVE-2023-23759 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences