CVE-2026-15712: libsoup3 Out-of-bounds Read
Vulnerability summary
CVE-2026-15712 is a medium (CVSS 5.9) Out-of-bounds Read vulnerability in libsoup3. EPSS estimates a 0.50% chance of exploitation in the next 30 days, higher than 41.7% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 2 · Related 2Timeline
- 14-07-2026PublishedVulnerability first disclosed.
- 14-07-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.50%
Chance of exploitation in the next 30 days
Percentile
42%
Versus all other CVEs
30-day change
-0.16 pp
From 0.66% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian1 product
- libsoup3All versions (No fix recorded) | < 3.8.0-1
Ubuntu1 product
- libsoup3All versions (No fix recorded)
2 vendors · 2 products
