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Vulnerability · Published Jun 22, 2026 · Assigned by redhat

CVE-2026-12549Libsoup: incomplete fix for cve-2026-2443: range suffix overflow in libsoup soupserver

Medium 4.8

In plain English

A medium-severity security flaw in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.8Medium
Exploit odds (30 days)0.4%top 70.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:14libsoup33.8.0-1DEBIAN-CVE-2026-12549
Ubuntu:22.04:LTSlibsoup2.42.74.2-3ubuntu0.9UBUNTU-CVE-2026-12549
Ubuntu:24.04:LTSlibsoup2.42.74.3-6ubuntu1.9UBUNTU-CVE-2026-12549
Ubuntu:25.10libsoup2.4no fix listedUBUNTU-CVE-2026-12549
Ubuntu:26.10libsoup2.4no fix listedUBUNTU-CVE-2026-12549
Ubuntu:24.04:LTSlibsoup33.4.4-5ubuntu0.9UBUNTU-CVE-2026-12549
Ubuntu:25.10libsoup3no fix listedUBUNTU-CVE-2026-12549
Ubuntu:26.04:LTSlibsoup33.6.6-1ubuntu0.1UBUNTU-CVE-2026-12549
Ubuntu:26.10libsoup33.6.6-1ubuntu3UBUNTU-CVE-2026-12549

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat Enterprise Linux 10 see references
Red Hat Red Hat Enterprise Linux 6 see references
Red Hat Red Hat Enterprise Linux 7 see references
Red Hat Red Hat Enterprise Linux 8 see references
Red Hat Red Hat Enterprise Linux 9 see references

Weakness: CWE-805 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L

References