Answer in brief
CVE-2026-74660 records a High severity (CVSS 7.8) vulnerability in netfilter: ebt_nflog: pin the NFLOG backend. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | 4.12 | Not reported |
| Linux/Linuxgeneric | >=c83fa19603bdaeef17b815713dbbe3230c8a34ee <3bcce49d617c593c7606083bfdb464a1761fa68d || >=c83fa19603bdaeef17b815713dbbe3230c8a34ee <394d7939c6b2b9e6bea0844c89efb5913168d898 || >=c83fa19603bdaeef17b815713dbbe3230c8a34ee <2cac4294f184c9bc19ff82552c62b80498694c39 || >=c83fa19603bdaeef17b815713dbbe3230c8a34ee <9d8a94b48b393885e7f876c8ef68ed4da5012078 || >=c83fa19603bdaeef17b815713dbbe3230c8a34ee <6809379a860b9fccbb5435bf08343f6d081ac68d || >=c83fa19603bdaeef17b815713dbbe3230c8a34ee <47a119ec8a7e2d5c8c4e86fb1a56c4e696e500fb || >=c83fa19603bdaeef17b815713dbbe3230c8a34ee <e2ab7e878bdbe80104c879c31fd2d82a476703b8 || >=c83fa19603bdaeef17b815713dbbe3230c8a34ee <30825970339c107bacaf7f61af90fcdb1f597ca1 | 3bcce49d617c593c7606083bfdb464a1761fa68d, 394d7939c6b2b9e6bea0844c89efb5913168d898, 2cac4294f184c9bc19ff82552c62b80498694c39, 9d8a94b48b393885e7f876c8ef68ed4da5012078, 6809379a860b9fccbb5435bf08343f6d081ac68d, 47a119ec8a7e2d5c8c4e86fb1a56c4e696e500fb, e2ab7e878bdbe80104c879c31fd2d82a476703b8, 30825970339c107bacaf7f61af90fcdb1f597ca1 |
Published upstream
Aug 22, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 22, 2026
In the Linux kernel, the following vulnerability has been resolved: netfilter: ebt_nflog: pin the NFLOG backend nf_log_unregister() runs after the per-net teardown so its final RCU grace period also drains readers that obtained the logger from a per-net binding. However, ebt_nflog passes an explicit ULOG log type to nf_log_packet() without holding a reference on the selected logger module, unlike the xt_NFLOG and nft_log frontends. An ebtables nflog rule can therefore remain callable while nfnetlink_log is unloaded. The resulting interleaving is: CPU 0 CPU 1 nfnetlink_log_fini() unregister_pernet_subsys() kfree(nfnl_log_pernet(net)) ebt_nflog_tg() nf_log_packet() nfulnl_log_packet() instance_lookup_get_rcu() The global ULOG logger is still registered at this point, so CPU 1 dereferences the per-net state after CPU 0 has freed it. KASAN reported: BUG: KASAN: slab-use-after-free in instance_lookup_get_rcu Read of size 8 at addr ff110001052e6210 by task poc/92 Call Trace: instance_lookup_get_rcu+0x1ce/0x1f0 [nfnetlink_log] nfulnl_log_packet+0x248/0x2fb0 [nfnetlink_log] nf_log_packet+0x204/0x300 ebt_nflog_tg+0x351/0x550 ebt_do_table+0xedf/0x22b0 Allocated by task 90: __kmalloc_noprof+0x186/0x470 ops_init+0x6d/0x420 register_pernet_operations+0x2f6/0x670 register_pernet_subsys+0x23/0x40 Freed by task 93: kfree+0x131/0x3c0 ops_undo_list+0x3e3/0x700 unregister_pernet_operations+0x232/0x490 unregister_pernet_subsys+0x1c/0x30 nfnetlink_log_fini+0x34/0x450 [nfnetlink_log] Acquire the ULOG logger module reference when an ebt_nflog rule is validated and release it when the rule is destroyed. Request the NFLOG backend for legacy callers when needed, matching xt_NFLOG. This prevents module teardown until all ebt_nflog rules have stopped using the logger.
Quoted source text, attributed separately from HOL analysis.