CVE-2026-3633: Libsoup2.4 · A flaw was found in libsoup
Affects libsoup2.4Source GCVE Database
Not known to be exploited · CVSS 3.9 Low.
Data as of 3 Nov 2026, 23:30 UTC
Thin evidence
One scorer or none| CNA (redhat) | CVSS 3.1 | 3.9 |
|---|
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:LExploitation evidence
Disclosed: evidence found.
CVE published 17 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10libsoup2.4pkg:deb/ubuntu/libsoup2.4?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10libsoup3pkg:deb/ubuntu/libsoup3?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlibsoup3pkg:deb/ubuntu/libsoup3?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu Pro 26.04 LTSlibsoup2.4pkg:deb/ubuntu/libsoup2.4?arch=source&distro=esm-apps/resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10libsoup2.4pkg:deb/ubuntu/libsoup2.4?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10libsoup3pkg:deb/ubuntu/libsoup3?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is available, users should consider restricting or sanitizing inputs that control the method parameter in soup_message_new() where possible to mitigate injection risk.
Description
A CRLF injection vulnerability exists in libsoup2.4 due to improper escaping of the method parameter in the soup_message_new() function. This flaw allows a remote attacker to inject arbitrary HTTP headers and additional request data by controlling the method value. The vulnerability affects multiple specific versions of libsoup2.4 and has a medium severity rating with a CVSS score of 6.5.