All vulnerabilities
CVE-2026-102559

Red Hat Enterprise Linux 10: Libsoup: libsoup: heap buffer overflow during websocket client-frame masking

Red Hat Red Hat Enterprise Linux 10Operating systems
Open in ThreatlineRecord JSON
CVSS
8.6High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.40%Chance of exploitation activity in the next 30 days, higher than 33% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published29 Sep 2026Updated 19 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Description

A flaw was found in libsoup. When constructing a masked WebSocket client frame for a very large outgoing payload, size values passed to GByteArray allocation APIs could be truncated while the masking routine still used the full length, causing a heap buffer overflow.

Text from CVE List

Affected versions 3

  • Red Hat Enterprise Linux 10unaffected: 0:3.6.5-3.el10_2.20 and laterCVE List
  • Red Hat Enterprise Linux 8unaffected: 0:2.62.3-19.el8_10 and laterCVE List
  • Red Hat Enterprise Linux 9unaffected: 0:2.72.0-16.el9_8.8 and laterCVE List

References 5