CVE-2026-15711 Denial of service in Red Hat Enterprise Linux 10
Remote attackers can crash applications using libsoup WebSockets by sending oversized control frames, causing a 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-2026-15711?
CVE-2026-15711 is a high-severity denial of service vulnerability in Red Hat Enterprise Linux 10, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability was found in libsoup's WebSocket frame parsing implementation. The library fails to validate length rules specified in RFC 6455 §5.5, which mandates that all WebSocket control frames (e.g., PING, PONG, CLOSE) contain a payload of 125 bytes or less. A remote, unauthenticated attacker can exploit this by sending a non-compliant, oversized control frame. Because the parser handles this protocol violation improperly instead of throwing an immediate connection termination error, it triggers a internal processing crash, resulting in a remote denial of service (DoS) for applications utilizing libsoup WebSockets.
Weakness: CWE-770
Which versions are affected by CVE-2026-15711?
Linux distribution packages (9)
libsoup AlmaLinux:8 | All versions | 2.62.3-15.el8_10 |
libsoup-devel AlmaLinux:8 | All versions | 2.62.3-15.el8_10 |
libsoup-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:2.62.3-15.el8_10 |
libsoup-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 0:2.62.3-15.el8_10 |
libsoup-devel Red Hat:enterprise_linux:8::appstream | All versions | 0:2.62.3-15.el8_10 |
libsoup Red Hat:enterprise_linux:8::baseos | All versions | 0:2.62.3-15.el8_10 |
libsoup-debuginfo Red Hat:enterprise_linux:8::baseos | All versions | 0:2.62.3-15.el8_10 |
libsoup-debugsource Red Hat:enterprise_linux:8::baseos | All versions | 0:2.62.3-15.el8_10 |
libsoup Rocky Linux:8 | All versions | 0:2.62.3-15.el8_10 |
How do I fix CVE-2026-15711?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-15711 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-15711 exists.
Sources
Also known as ALSA-2026:68266, AZL-92400, DEBIAN-CVE-2026-15711, ECHO-e22f-3a38-1187, GHSA-w948-qrw5-cffc, OESA-2026-3779 and 7 more.