Quick answers
- Is CVE-2026-121577 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-121577 being exploited in the wild.
- How severe is CVE-2026-121577?
- Informational severity, published 3 November 2026.
- Which products and versions are affected?
- Whatstk 0.2.0 before 0.9.0.
- Is there a fix for CVE-2026-121577?
- Yes: fixed in 0.9.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-121577 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-121577?
- Check whether you run Whatstk at an affected version. 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.
How to fix
- Fixed in: 0.9.0
Technical details
The generate_regex() function in whatstk/whatsapp/parser.py fails to escape regular expression metacharacters when building the header pattern from auto-detected format strings. When a chat export contains metacharacters like +, *, |, ?, (, ), \, ^, or $ as date separators, they are interpreted as regex operators rather than literals, causing catastrophic backtracking or unhandled exceptions. An attacker who supplies a malicious chat export can trigger unbounded CPU consumption or crash the parser.
Affected products
- whatstk whatstk 0.2.0 before 0.9.0
Timeline
- 2026-11-03: disclosed