CVE-2026-15712
MEDIUM 5.9 PoC AVAILABLEA 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.
Public exploit or PoC code exists. Modeled probability is still low, but the barrier to attack is reduced — watch closely.
Exploitation likelihood
0.5%chance of exploitation in 30 days · 39th percentile
Impact if exploited
5.9CVSS 3.1 · MEDIUM
- ConfidentialityNone
- IntegrityNone
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ⚠Complexity: Needs a race window or specific setup
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- reference https://gitlab.gnome.org/GNOME/libsoup/-/work_items/540
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-15712/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-15712/poc.json
Weakness (CWE)
- CWE-125: Out-of-bounds Read
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
All CVSS metrics
- MEDIUM 5.9 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - MEDIUM 5.9 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H