CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2026-42304
High (7.5) in twisted twisted. EPSS 0.4% chance of exploitation in the next 30 days. Fixed in twisted 26.4.0, 26.4.0rc2.
Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.4.0rc2, the twisted.names module is vulnerable to a Denial of Service (DoS) attack via resource exhaustion during DNS name decompression. A remote, unauthenticated attacker can exploit this by sending a crafted TCP DNS packet containing deeply chained compression pointers. This flaw bypasses previous loop-prevention logic, causing the single-threaded Twisted reactor to hang while processing millions of recursive lookups, effectively freezing the server. This vulnerability is fixed in 26.4.0rc2.
Severity
- EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 37% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-400, CWE-407
- Published
- Modified
- Record from
- the NVD, synced
Affected
- twisted:twisted
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-grgv-6hw6-v9g4 | PyPI | twisted | <26.4.0rc2 | 26.4.0rc2 |
| PYSEC-2026-160 | PyPI | twisted | <26.4.0 | 26.4.0 |