CVE-2026-12549 Libsoup: incomplete fix for cve-2026-2443: range suffix overflow in libsoup soupserver
An integer overflow in Libsoup's Range request handling causes malformed responses and log flooding, potentially leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-12549?
CVE-2026-12549 is a medium-severity vulnerability in Redhat Enterprise Linux, published on 22 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-805
Which versions are affected by CVE-2026-12549?
It affects 2 products.
Products include Gnome Libsoup, Redhat Enterprise Linux.
How do I fix CVE-2026-12549?
Apply the vendor's patch.
Is CVE-2026-12549 being exploited?
There is no known exploitation of CVE-2026-12549 in the wild and no public exploit code.
Other vulnerabilities in Redhat Enterprise Linux
- CVE-2026-102556 Libsoup: libsoup: heap buffer overflow from websocket pong signal type confusion
- CVE-2026-102557 Libsoup: libsoup: heap buffer overflow during websocket message reassembly
- CVE-2026-102558 Libsoup: libsoup: heap buffer overflow during websocket receive-buffer growth
- CVE-2026-102559 Libsoup: libsoup: heap buffer overflow during websocket client-frame masking
- CVE-2026-102560 Libsoup: libsoup: heap buffer overflow during outgoing permessage-deflate buffer growth
Sources
Also known as CLSA-2026-1784191279, CLSA-2026-1784192091, DEBIAN-CVE-2026-12549, GHSA-7gwx-vgp2-4hmg, UBUNTU-CVE-2026-12549.