Answer in brief
CVE-2026-74748 records a Unknown severity 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.
A CVSS score is not reported in the current record. 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 26, 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.