CVE-2026-12478

MEDIUM 4.8

Libsoup: incomplete fix for cve-2026-0716: out-of-bounds read in libsoup websocket frame processing (unmasked path)

CVSS Score

4.8

EPSS Score

0.0%

EPSS Percentile

0th

The fix for CVE-2026-0716 (commit 6ff7ef0, libsoup 3.6.6) placed the integer overflow guard inside the if (masked) block, leaving unmasked server-to-client frames unprotected. A malicious WebSocket server can send a crafted unmasked frame with a payload length near UINT64_MAX to trigger an OOB read in a libsoup-based client when max_incoming_payload_size is set to 0.

CWE	CWE-125
Vendor	red hat
Product	red hat enterprise linux 10
Published	Jul 14, 2026
Last Updated	Jul 15, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

Low

Affected Versions

Red Hat / Red Hat Enterprise Linux 10

All versions affected

References

NVD ↗ CVE.org ↗ EPSS Data ↗

access.redhat.com: https://access.redhat.com/security/cve/CVE-2026-12478 access.redhat.com: https://access.redhat.com/security/cve/cve-2026-0716 bugzilla.redhat.com: https://bugzilla.redhat.com/show_bug.cgi?id=2489655 gitlab.gnome.org: https://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/518

Credits

Red Hat would like to thank Adel Bouachraoui and Gerard Capdevila for reporting this issue.