CVE-2026-6324: Libsoup2.4 · A flaw was found in libsoup
Affects libsoup2.4Source GCVE Database
Not known to be exploited · CVSS 4.8 Medium · fixed in 3.0.7-0ubuntu1+esm9 : update libsoup2.4 when convenient.
Data as of 3 Nov 2026, 23:30 UTC
Thin evidence
One scorer or none| CNA (redhat) | CVSS 3.1 | 4.8 |
|---|
- Patch
- Available – fixed in 3.0.7-0ubuntu1+esm9, 3.4.4-5ubuntu0.9, 3.6.6-1ubuntu3 +1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 29 May 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
Upgrade to a fixed release listed under Affected software.
Patches and advisories
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 LTSlibsoup2.4pkg:deb/ubuntu/libsoup2.4?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlibsoup3pkg:deb/ubuntu/libsoup3?arch=source&distro=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
A patch is available and should be applied. Fixed versions include 3.0.7-0ubuntu1+esm9, 3.4.4-5ubuntu0.9, 3.6.6-1ubuntu3, and 3.6.6-1ubuntu0.1. Users should upgrade to these or later versions to remediate the vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Description
A vulnerability in libsoup2.4's soup_body_input_stream_read_chunked() function allows a remote attacker to exploit an unsigned to signed conversion error by sending a malicious HTTP request. This flaw occurs when libsoup is used behind a non-libsoup proxy or as a proxy in front of a non-libsoup backend. Exploitation can lead to bypassing security controls, web cache poisoning, or unauthorized access. The vulnerability requires a specialized network setup involving HTTP keep-alive connection reuse and differing chunk-parsing logic between proxies. It has a medium severity rating with a CVSS score of 4.8 and has been fixed in versions 3.0.7-0ubuntu1+esm9 and later.
References
- ubuntu.com/security/CVE-2026-6324 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-6324 (opens in a new tab)
- gitlab.gnome.org/GNOME/libsoup/-/issues/508 (opens in a new tab)
- gitlab.gnome.org/GNOME/libsoup/-/merge_requests/517 (opens in a new tab)
- gitlab.gnome.org/GNOME/libsoup/-/commit/96ac392b444d01bd5de1d1276b187c3ed49d048c (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-6324 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2458479 (opens in a new tab)
- ubuntu.com/security/notices/USN-8890-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8890-2 (opens in a new tab)