Answer in brief
CVE-2026-74748 records a High severity (CVSS 7.8) vulnerability in netfilter: ipset: fix refcount race between list:set GC and swap. 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 | >=9076aea76538556224e7d73ab718f8841330818a <97a01de0c6321b7210d30d0a4d60f10f561097c7 || >=9076aea76538556224e7d73ab718f8841330818a <c21afc7c216a4d257a4f3f300e0791890bc846b9 || >=9076aea76538556224e7d73ab718f8841330818a <b0aab9dd1a348b99d75ff52765719d0cc2050630 || >=9076aea76538556224e7d73ab718f8841330818a <b891e7a6bb06e0f6560e5932665ac660acd12225 || >=9076aea76538556224e7d73ab718f8841330818a <20cb13a523f0a05cb2d0a7d72abae687683712e0 || >=9076aea76538556224e7d73ab718f8841330818a <cb20da33839f28f590c99f16bafaa6151451c0e8 || >=9076aea76538556224e7d73ab718f8841330818a <24ffcb1e1688c55fd2a505f064295cd28eac546d || >=9076aea76538556224e7d73ab718f8841330818a <0c88868271653537ed443272dd8e7d13634d214b | 97a01de0c6321b7210d30d0a4d60f10f561097c7, c21afc7c216a4d257a4f3f300e0791890bc846b9, b0aab9dd1a348b99d75ff52765719d0cc2050630, b891e7a6bb06e0f6560e5932665ac660acd12225, 20cb13a523f0a05cb2d0a7d72abae687683712e0, cb20da33839f28f590c99f16bafaa6151451c0e8, 24ffcb1e1688c55fd2a505f064295cd28eac546d, 0c88868271653537ed443272dd8e7d13634d214b |
| Linux/Linuxgeneric | 3.8 | Not reported |
Published upstream
Aug 26, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 27, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 26, 2026
In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: fix refcount race between list:set GC and swap __ip_set_put_byindex() resolved the index to a set pointer under RCU, then took ip_set_ref_lock in __ip_set_put() to decrement set->ref. ip_set_swap() holds that same lock while swapping both the ip_set_list slots and the two sets' ref counters, so it can interleave between the dereference and the lock acquisition, leaving the caller to decrement a set whose reference already moved to the other index and hit BUG_ON(set->ref == 0). list_set_gc() reaches this from timer softirq, which the nfnl mutex does not serialize against swap: an expiring list:set member calls list_set_del() -> ip_set_put_byindex() while IPSET_CMD_SWAP runs on the referenced sets. Resolve the index and decrement under ip_set_ref_lock, as ip_set_swap() already does, keeping the refcount tied to the index rather than to a stale set pointer. kernel BUG at net/netfilter/ipset/ip_set_core.c:685! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI RIP: 0010:ip_set_put_byindex (net/netfilter/ipset/ip_set_core.c:870) Call Trace: <IRQ> list_set_del (net/netfilter/ipset/ip_set_list_set.c:159) set_cleanup_entries (net/netfilter/ipset/ip_set_list_set.c:181) list_set_gc (net/netfilter/ipset/ip_set_list_set.c:578) call_timer_fn (kernel/time/timer.c:1748) __run_timers (kernel/time/timer.c:1799 kernel/time/timer.c:2374) run_timer_softirq (kernel/time/timer.c:2405) </IRQ> Kernel panic - not syncing: Fatal exception in interrupt
Quoted source text, attributed separately from HOL analysis.