Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| twisted | twisted | < 26.4.0rc2 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | twisted | 26.4.0-1 | — |
| Debian 13 | twisted | No fix yet | — |
| Debian 12 | twisted | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | twisted | 25.5.0-5ubuntu0.1 | USN-8380-1 |
| Ubuntu 25.10 | twisted | 24.11.0-1ubuntu0.1 | USN-8380-1 |
| Ubuntu 24.04 LTS | twisted | 24.3.0-1ubuntu0.2 | USN-8380-1 |
| Ubuntu 22.04 LTS | twisted | 22.1.0-2ubuntu2.7 | USN-8380-1 |
| Ubuntu 20.04 LTS | twisted | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | twisted | No fix yet | — |
| Ubuntu Pro 16.04 LTS | twisted | No fix yet | — |
| Ubuntu Pro 14.04 LTS | twisted | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | python-Twisted | 24.10.0-160000.3.1 | SUSE-SU-2026:22004-1 |
| SLES 16.0 | python-Twisted | 24.10.0-160000.3.1 | SUSE-SU-2026:22004-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | python-Twisted | 26.4.0-1.1 | openSUSE-SU-2026:10759-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | python3-twisted +1 | 22.4.0-129.amzn2023.0.6 | ALAS2023-2026-1734 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | python-twisted | 22.10.0-5 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | twisted | < 26.4.0rc2 | 26.4.0rc2 | GHSA-grgv-6hw6-v9g4 |
| PyPI | twisted | < 26.4.0 | 26.4.0 | PYSEC-2026-160 |
Advisories 5
- WID-SEC-2026-2455 Oracle Solaris Drittanbieterkomponenten: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- SUSE-SU-2026:22004-1 Security update for python-Twisted SUSE / openSUSE Security Updates · Jun 9, 2026
- USN-8380-1 twisted vulnerability Ubuntu Security Notices (USN) · Jun 3, 2026
- ALAS2023-2026-1734 Important: python-twisted security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · May 26, 2026
- openSUSE-SU-2026:10759-1 python-Twisted-doc-26.4.0-1.1 on GA media SUSE / openSUSE Security Updates · May 13, 2026