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Red HatCVE-2026-12478

Red Hat Enterprise Linux: integer overflow

Medium4.8CVE-2026-12478 · Published Jul 14, 2026 · updated Sep 16, 2026

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.

Red Hat advisory

Affected versions

PackageAffectedFixed in
Red Hat Enterprise Linux 10
Product
all versionsNo fix yet
Red Hat Enterprise Linux 6
Product
all versionsNo fix yet
Red Hat Enterprise Linux 7
Product
all versionsNo fix yet
Red Hat Enterprise Linux 8
Product
all versionsNo fix yet
Red Hat Enterprise Linux 9
Product
all versionsNo fix yet
Details and references

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