Quick answers
- Is CVE-2026-77642 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-77642 being exploited in the wild.
- How severe is CVE-2026-77642?
- High severity, with a CVSS score of 7.5, published 20 August 2026.
- Which products and versions are affected?
- Tor Project Tor before 0.4.9.9.
- Is there a fix for CVE-2026-77642?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-77642 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-77642?
- Check whether you run Torproject Tor. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is an out-of-bounds write that occurs during parsing of consensus documents or detached signatures when an unexpected signature digest type is encountered. The flaw exists in signature validation logic and can result in memory corruption. Attack vectors include network delivery of malformed consensus data; directory authorities are at heightened risk due to their role in validating and relaying network consensus. The vulnerability is fixed in Tor 0.4.9.9 and later versions.
Affected products
- Tor Project Tor before 0.4.9.9
Timeline
- 2026-08-20: disclosed