Vulnerability · Published Oct 6, 2026 · Assigned by GitHub_M
CVE-2026-106454Twisted: IMAP wildcardToRegexp() ReDoS
Medium 4.3
In plain English
A medium-severity regular-expression denial of service in twisted from twisted. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Twisted is an event-based framework for internet applications, supporting Python 3.6+. In 25.5.0 and earlier, wildcardToRegexp() in twisted/mail/imap4.py translates the IMAP asterisk and percent wildcards but passes all other characters from an authenticated client's LIST or LSUB pattern directly to re.compile(), allowing nested or otherwise expensive regular expression constructs to cause catastrophic backtracking when matched against mailbox names. Because Twisted uses a cooperative single-threaded reactor, the blocking match suspends all server input and output for the duration of the match. No fixed release is available as of this review.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | twisted | no fix listed | DEBIAN-CVE-2026-106454 |
| Debian:13 | twisted | no fix listed | DEBIAN-CVE-2026-106454 |
| Debian:14 | twisted | 26.4.0-5 | DEBIAN-CVE-2026-106454 |
| PyPI | twisted | no fix listed | PYSEC-2026-4304 |
| PyPI | twisted | no fix listed | GHSA-8pqf-f4m5-798g |
| Ubuntu:22.04:LTS | twisted | 22.1.0-2ubuntu2.8 | USN-9000-1 |
| Ubuntu:22.04:LTS | twisted | 22.1.0-2ubuntu2.8 | UBUNTU-CVE-2026-106454 |
| Ubuntu:24.04:LTS | twisted | 24.3.0-1ubuntu0.3 | USN-9000-1 |
| Ubuntu:24.04:LTS | twisted | 24.3.0-1ubuntu0.3 | UBUNTU-CVE-2026-106454 |
| Ubuntu:26.04:LTS | twisted | 25.5.0-5ubuntu0.2 | UBUNTU-CVE-2026-106454 |
| Ubuntu:26.04:LTS | twisted | 25.5.0-5ubuntu0.2 | USN-9000-1 |
| Ubuntu:26.10 | twisted | 26.4.0-4ubuntu0.1 | USN-9000-1 |
| Ubuntu:26.10 | twisted | 26.4.0-4ubuntu0.1 | UBUNTU-CVE-2026-106454 |
Affected products (as reported)
Weakness: CWE-1333 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
References
- https://github.com/twisted/twisted/security/advisories/GHSA-8pqf-f4m5-798g x_refsource_CONFIRM
- https://github.com/twisted/twisted/pull/12788 x_refsource_MISC
- https://github.com/twisted/twisted/commit/2f8a3c29246f4eb324690e06a9767a11dc4aec9f x_refsource_MISC