A use-after-free flaw was found in the X.Org X server and Xwayland in FreeCounter(). A client that sets up multiple SyncCounters and awaits on those triggers can trigger a use-after-free when destroying those counters via a second client connection. This may be used to crash the server, or for privilege escalation if the X server runs as root.
| Score | Percentile |
|---|---|
| 0.15% | 4.91% |
| Base score | Version | Severity | Vector |
|---|---|---|---|
| 7.8 | 3.1 | — |
|
| Type | Value |
|---|---|
| GHSA | GHSA-7j37-rf7v-jf5c ↗ |
| CVE | CVE-2026-50260 ↗ |
| CWE id | Name |
|---|---|
| CWE-416 | Use After Free |