CVE-2026-15712: Libsoup3 · A heap buffer over-read vulnerability was discovered in libsoup's (versions: libsoup 3.0 to
Affects libsoup3Source GCVE Database
Not known to be exploited · CVSS 5.9 Medium.
Data as of 3 Nov 2026, 23:14 UTC
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 14 Jul 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 26.10libsoup3pkg: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 24.04 LTSlibsoup3pkg:deb/ubuntu/libsoup3?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu Pro 22.04 LTSlibsoup3pkg:deb/ubuntu/libsoup3?arch=source&distro=esm-apps/jammyOther threats | Affected
| Fixed in– |
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Description
A heap buffer over-read vulnerability was discovered in libsoup's (versions: libsoup 3.0 to 3.7.0) HTTP/2 connection tracking framework. When the library processes an HTTP/2 GOAWAY frame, it improperly handles the "Additional Debug Data" payload by assuming the data stream is a safely NUL-terminated C-string. Because the parser lacks strict length-boundary verification before reading this data, a remote, unauthenticated attacker can intentionally send a malformed GOAWAY frame missing the appropriate null delimiter. This causes the library to read past the end of the allocated buffer, triggering an application crash that results in a denial of service (DoS), or potentially exposing fragments of memory contents.
References
- ubuntu.com/security/CVE-2026-15712 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-15712 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-15712 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2499939 (opens in a new tab)
- gitlab.gnome.org/GNOME/libsoup/-/work_items/540 (opens in a new tab)