DirtyClone (CVE-2026-43503, CVSS 8.8): LPE via XFRM/IPsec path when __pskb_copy_fclone() drops SKBFL_SHARED_FRAG flag during netfilter TEE packet cloning. Bypasses DirtyFrag mitigations (CVE-2026-43284, CVE-2026-43500) and Fragnesia (CVE-2026-46300).
Attack: unprivileged user creates network namespace (CAP_NET_ADMIN), configures loopback IPsec tunnel, uses TEE rule to trigger vulnerable clone path, performs in-place ESP decryption writing to page-cache-backed /usr/bin/su memory → silent root.
Fixed in Linux v7.1-rc5 (May 21, 2026). Workarounds: kernel.unprivileged_userns_clone=0, blacklist esp4/esp6/rxrpc modules. Confirmed on Debian, Ubuntu, Fedora with unprivileged user namespaces.
JFrog developed working PoC; no public PoC existed at disclosure. Reported May 19; coincided with original DirtyFrag researcher Hyunwoo Kim report May 16.