Summary
It was discovered that Python's http.client did not properly handle the
Content-Length header in HTTP responses. A malicious server could exploit
this to cause Python to allocate excessive memory, leading to a denial of
service.
Fixed packages 8
| Release | Package | Fixed in |
|---|---|---|
| Ubuntu · 22.04 LTS 22.04:LTS | python3.10 | 3.10.12-1~22.04.13 |
| Ubuntu · 24.04 LTS 24.04:LTS | python3.12 | 3.12.3-1ubuntu0.10 |
| Ubuntu · 25.10 | python3.13 | 3.13.7-1ubuntu0.2 |
| Ubuntu · 25.10 | python3.14 | 3.14.0-1ubuntu0.1 |
| Ubuntu · Pro 18.04 LTS Pro:18.04:LTS | python3.8 | 3.8.0-3ubuntu1~18.04.2+esm8 |
| Ubuntu · Pro 20.04 LTS Pro:20.04:LTS | python3.8 | 3.8.10-0ubuntu1~20.04.18+esm4 |
| Ubuntu · Pro 20.04 LTS Pro:20.04:LTS | python3.9 | 3.9.5-3ubuntu0~20.04.1+esm8 |
| Ubuntu · Pro 22.04 LTS Pro:22.04:LTS | python3.11 | 3.11.0~rc1-1~22.04.1~esm7 |
Vulnerabilities 1
-
Medium 6.3
Excessive read buffering DoS in http.client
When reading an HTTP response from a server, if no read amount is specified, the default behavior will be to use Content-Length. This allows a malicious server to cause the client to read large amounts of data into memory, potentially causing OOM or other DoS.
References
-
report
https://ubuntu.com/security/CVE-2025-13836