HighFix available
libsoup3 — security advisory
A flaw was found in libsoup, a library for handling HTTP requests. This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation. A remote attacker can exploit this by sending specially crafted HTTP/2 requests that cause authentication failures. This can lead to the application attempting to access memory that has already been freed, potentially causing application instability or crashes, resulting in a Denial of Service (DoS).
- Products
- libsoup3
- Affected versions
- 3.4.2-4, 3.4.4-1, 3.4.4-2, 3.4.4-4, 3.4.4-5, 3.4.4-5build1, 3.4.4-5build2, 3.4.4-5ubuntu0.1, 3.4.4-5ubuntu0.2, 3.4.4-5ubuntu0.3, 3.4.4-5ubuntu0.4, 3.4.4-5ubuntu0.5, 3.4.4-5ubuntu0.6, 3.4.4-5ubuntu0.7, 3.4.4-5ubuntu0.8, 3.6.5-1, 3.6.5-1ubuntu1, 3.6.5-3, 3.6.5-4, 3.6.5-4ubuntu0.1, 3.6.5-4ubuntu0.2, 3.6.5-5, 3.6.5-6, 3.6.5-7, 3.6.5-9, 3.6.6-1
- Fixed versions
- 3.4.4-5ubuntu0.9, 3.6.6-1ubuntu0.1, 3.6.6-1ubuntu3
- CVEs
- CVE-2026-4271
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 17:41 UTC · Revision 1
Source evidence
A flaw was found in libsoup, a library for handling HTTP requests. This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation. A remote attacker can exploit this by sending specially crafted HTTP/2 requests that cause authentication failures. This can lead to the application attempting to access memory that has already been freed, potentially causing application instability or crashes, resulting in a Denial of Service (DoS).
osv:UBUNTU-CVE-2026-4271
libsoup3
Fixed versions: 3.4.4-5ubuntu0.9
libsoup3
Fixed versions: Not specified
libsoup3
Fixed versions: 3.6.6-1ubuntu3
libsoup3
Fixed versions: 3.6.6-1ubuntu0.1
Complete source record
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