CVE-2026-12549 — MEDIUM (4.8)

Vulnerability Description

The fix for CVE-2026-2443 was regressed by a subsequent rework commit that replaced specific overflow checks with a general signed comparison. When a client sends a Range request with a suffix length exceeding the content size, the resulting negative start value is not properly clamped, leading to malformed HTTP 206 responses and log flooding.

CVSS Score

4.8

MEDIUM

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 Products

Vendor	Product	Versions
Redhat	Enterprise Linux	6.0
Gnome	Libsoup	-

Related Weaknesses (CWE)

CWE-805

References

https://access.redhat.com/security/cve/CVE-2026-12549Vendor AdvisoryMitigation
https://access.redhat.com/security/cve/cve-2026-0716Vendor AdvisoryMitigation
https://bugzilla.redhat.com/show_bug.cgi?id=2489999Issue TrackingVendor Advisory
https://gitlab.gnome.org/GNOME/libsoup/-/work_items/516ExploitIssue TrackingPatch

FAQ

What is CVE-2026-12549?

CVE-2026-12549 is a vulnerability with a CVSS score of 4.8 (MEDIUM). The fix for CVE-2026-2443 was regressed by a subsequent rework commit that replaced specific overflow checks with a general signed comparison. When a client sends a Range request with a suffix length ...

How severe is CVE-2026-12549?

CVE-2026-12549 has been rated MEDIUM with a CVSS base score of 4.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-12549?

Check the references section above for vendor advisories and patch information. Affected products include: Redhat Enterprise Linux, Gnome Libsoup.