CVE-2026-43284: xfrm: esp: avoid in-place decrypt on shared skb frags

The “Dirty Frag” vulnerability is a chained local privilege escalation (LPE) issue in the Linux kernel that combines flaws in the ESP/XFRM and RXRPC subsystems to allow an unprivileged local attacker to gain root access on major Linux distributions. The attack abuses kernel page-cache manipulation and network protocol handling to overwrite privileged binaries and execute arbitrary code with elevated privileges. Exploitation differs by distribution: the ESP issue affects systems permitting unprivileged user namespaces, while the RXRPC issue impacts distributions with RXRPC enabled, such as Ubuntu. Together, the vulnerabilities provide broad cross-distribution root compromise capability, with mitigations involving disabling vulnerable kernel modules (esp4, esp6, and rxrpc) until upstream patches are fully merged and deployed.

— Red Hat

xfrm: esp: avoid in-place decrypt on shared skb frags

— Microsoft