Packages
- python-tornado - scalable, non-blocking web server and tools
Details
It was discovered that Tornado incorrectly handled special characters in
HTTP headers. An attacker could possibly use this issue to execute a cross-
site scripting (XSS) attack. This issue only affected Ubuntu 20.04 LTS,
Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 25.04, and Ubuntu 25.10.
(CVE-2025-67724)
It was discovered that Tornado incorrectly handled repeated HTTP headers.
An attacker could possibly use this issue to cause Tornado to use excessive
resources, causing a denial of service. (CVE-2025-67725)
It was discovered that Tornado incorrectly handled parsing of certain HTTP
header values. An attacker could possibly use this issue to cause Tornado
to use excessive resources, causing a denial of service. (CVE-2025-67726)
It was discovered that Tornado incorrectly handled special characters in
HTTP headers. An attacker could possibly use this issue to execute a cross-
site scripting (XSS) attack. This issue only affected Ubuntu 20.04 LTS,
Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 25.04, and Ubuntu 25.10.
(CVE-2025-67724)
It was discovered that Tornado incorrectly handled repeated HTTP headers.
An attacker could possibly use this issue to cause Tornado to use excessive
resources, causing a denial of service. (CVE-2025-67725)
It was discovered that Tornado incorrectly handled parsing of certain HTTP
header values. An attacker could possibly use this issue to cause Tornado
to use excessive resources, causing a denial of service. (CVE-2025-67726)
Update instructions
In general, a standard system update will make all the necessary changes.
Learn more about how to get the fixes.The problem can be corrected by updating your system to the following package versions:
| Ubuntu Release | Package Version | ||
|---|---|---|---|
| 25.10 questing | python3-tornado – 6.4.2-3ubuntu0.2 | ||
| 25.04 plucky | python3-tornado – 6.4.2-1ubuntu0.25.04.3 | ||
| 24.04 LTS noble | python3-tornado – 6.4.0-1ubuntu0.4 | ||
| 22.04 LTS jammy | python3-tornado – 6.1.0-3ubuntu0.1~esm4 | ||
| 20.04 LTS focal | python3-tornado – 6.0.3+really5.1.1-3ubuntu0.1~esm3 | ||
| 18.04 LTS bionic | python-tornado – 4.5.3-1ubuntu0.2+esm2 | ||
| python3-tornado – 4.5.3-1ubuntu0.2+esm2 | |||
| 16.04 LTS xenial | python-tornado – 4.2.1-1ubuntu3.1+esm2 | ||
| python3-tornado – 4.2.1-1ubuntu3.1+esm2 | |||
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