modules: add nft_catchall (CVE-2026-23111, nf_tables catch-all abort UAF)

The newest nftables LPE: a use-after-free in the nf_tables transaction-
abort path. An inverted condition (a stray '!') in
nft_map_catchall_activate() makes the abort path process active catch-all
map elements instead of skipping them; a catch-all GOTO element drives a
chain's use-count to zero so a following DELCHAIN frees it while the
catch-all verdict still references it -> UAF, escalatable from an
unprivileged user (userns + nftables) via modprobe_path/selinux_state ROP.
Fixed upstream by f41c5d1; CWE-416, CVSS 7.8; not in CISA KEV. Public
reproduction by FuzzingLabs.

Takes the corpus to 43 modules / 38 CVEs.

🟡 reconstructed trigger, primitive-only, NOT VM-verified — same contract
as nf_tables (CVE-2024-1086). detect() version-gates (catch-all elems
~5.13; Debian backports 6.1.164/6.12.73/6.18.10, 7.0+ inherits) AND
requires unprivileged user_ns clone (else PRECOND_FAIL). exploit() forks
an isolated child, builds a verdict map with a catch-all GOTO element,
provokes an aborting batch to drive the abort-path UAF, observes slabinfo,
and returns EXPLOIT_FAIL — the per-kernel leak + R/W + modprobe_path ROP
is not bundled. kernel_range table verified drift-clean against the live
Debian tracker (the 6.18 branch / 6.18.10 fix is the real forky/sid
backport; the earlier 7.0.10 figure was wrong).

Wired: registry, Makefile, safety rank (35), 6 detect() test rows (version
+ userns gating), CVE_METADATA.json + cve_metadata.c + KEV_CROSSREF.md
(sorted insert, CWE-416/T1068/not-KEV), README + CVES.md + website counts
(43/38) + yellow pill, RELEASE_NOTES v0.9.11, verify-vm target. Credit:
FuzzingLabs + upstream fix f41c5d1. Version 0.9.11.

core/cve_metadata.c

@@ -260,6 +260,14 @@ const struct cve_metadata cve_metadata_table[] = {
         .in_kev              = false,
         .kev_date_added      = "",
     },
+    {
+        .cve                 = "CVE-2026-23111",
+        .cwe                 = "CWE-416",
+        .attack_technique    = "T1068",
+        .attack_subtechnique = NULL,
+        .in_kev              = false,
+        .kev_date_added      = "",
+    },
     {
         .cve                 = "CVE-2026-31635",
         .cwe                 = "CWE-130",

core/registry.h

@@ -58,6 +58,7 @@ void skeletonkey_register_nft_pipapo(void);
 void skeletonkey_register_ptrace_pidfd(void);
 void skeletonkey_register_sudo_host(void);
 void skeletonkey_register_cifswitch(void);
+void skeletonkey_register_nft_catchall(void);
 
 /* Call every skeletonkey_register_<family>() above in canonical order.
  * Single source of truth so the main binary and the test binary stay

core/registry_all.c

@@ -54,4 +54,5 @@ void skeletonkey_register_all_modules(void)
     skeletonkey_register_ptrace_pidfd();
     skeletonkey_register_sudo_host();
     skeletonkey_register_cifswitch();
+    skeletonkey_register_nft_catchall();
 }