CVE-2026-102560: Libsoup2.4 · A flaw was found in libsoup
Affects libsoup2.4Source GCVE Database
Not known to be exploited · CVSS 8.6 High.
Data as of 3 Nov 2026, 22:58 UTC
Thin evidence
One scorer or none| CNA (redhat) | CVSS 3.1 | 8.6 |
|---|
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 29 Sep 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 24.04 LTSlibsoup2.4pkg:deb/ubuntu/libsoup2.4?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlibsoup3pkg:deb/ubuntu/libsoup3?arch=source&distro=nobleOther 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
Red Hat advises disabling the permessage-deflate WebSocket extension if it is not required. Additionally, outgoing message sizes should be capped to prevent triggering the buffer overflow. Until a fix is available, applying these mitigations reduces risk.
Description
A heap buffer overflow vulnerability exists in libsoup 2.4 when the permessage-deflate WebSocket extension compresses very large outgoing messages. The flaw arises from truncated size calculations that can wrap during GByteArray growth, causing zlib to write beyond the allocated buffer. This can lead to heap corruption or denial of service. Exploitation requires the permessage-deflate extension to be negotiated and large outgoing messages to be compressed. Mitigation includes disabling the permessage-deflate extension if not needed and limiting outgoing message sizes.
References
- ubuntu.com/security/CVE-2026-102560 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-102560 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2543296 (opens in a new tab)
- gitlab.gnome.org/GNOME/libsoup/-/work_items/554 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-102560 (opens in a new tab)