CVE-2026-74748

HIGHPre-NVD 7.87.8—
EchelonGraph scoreHIGH confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-08-27. a secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 5 sources updated this week
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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: 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) Kernel panic - not syncing: Fatal exception in interrupt

CVSS v3
7.8
EG Score
7.8(high)
EG Risk
40(Track)
EG Risk 40/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity78% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
4%
KEV
Not listed

Published

August 26, 2026

Last Modified

August 27, 2026

Advisory Details (8)

Auto-updated Aug 27, 2026
No patch confirmed yet.
generic

netfilter: ipset: fix refcount race between list:set GC and swap - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/cb20da33839f28f590c99f16bafaa6151451c0e8
generic

netfilter: ipset: fix refcount race between list:set GC and swap - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c21afc7c216a4d257a4f3f300e0791890bc846b9
generic

netfilter: ipset: fix refcount race between list:set GC and swap - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b891e7a6bb06e0f6560e5932665ac660acd12225
generic

netfilter: ipset: fix refcount race between list:set GC and swap - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b0aab9dd1a348b99d75ff52765719d0cc2050630
generic

netfilter: ipset: fix refcount race between list:set GC and swap - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/97a01de0c6321b7210d30d0a4d60f10f561097c7
generic

netfilter: ipset: fix refcount race between list:set GC and swap - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/24ffcb1e1688c55fd2a505f064295cd28eac546d
generic

netfilter: ipset: fix refcount race between list:set GC and swap - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/20cb13a523f0a05cb2d0a7d72abae687683712e0
generic

netfilter: ipset: fix refcount race between list:set GC and swap - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0c88868271653537ed443272dd8e7d13634d214b

Vendor Advisories for CVE-2026-74748(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Data Freshness Timeline

(refreshed 17× in last 7d / 17× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-30 05:39 UTCEG score recompute
  2. 2026-08-30 05:39 UTCGHSA enrichment
  3. 2026-08-30 01:22 UTCEPSS rescore
  4. 2026-08-29 17:48 UTCGHSA enrichment
  5. 2026-08-29 05:55 UTCEG score recompute
  6. 2026-08-29 05:55 UTCGHSA enrichment
  7. 2026-08-28 21:42 UTCEPSS rescore
  8. 2026-08-28 18:01 UTCGHSA enrichment
  9. 2026-08-28 06:08 UTCGHSA enrichment
  10. 2026-08-27 18:14 UTCEG score recompute
  11. 2026-08-27 18:13 UTCGHSA enrichment
  12. 2026-08-27 14:25 UTCEPSS rescore
  13. 2026-08-27 06:22 UTCEG score recompute▲ 7.80
  14. 2026-08-27 06:11 UTCMITRE cvelistV5CVSS v3 → 7.8 · severity → HIGH
  15. 2026-08-26 15:43 UTCNVD update
  16. 2026-08-26 14:43 UTCEG score recompute
  17. 2026-08-26 14:41 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-74748?
CVE-2026-74748 is a high vulnerability published on August 26, 2026. In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: fix refcount race between list:set GC and swap ipsetput_byindex() resolved the index to a set pointer under RCU, then took ipsetreflock in ipset_put() to decrement set->ref. ipsetswap() holds that same lock while…
When was CVE-2026-74748 disclosed?
CVE-2026-74748 was first published in the National Vulnerability Database on August 26, 2026, with the most recent update on August 27, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-74748 actively exploited?
CVE-2026-74748 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 96.5% of all scored CVEs.
What is the CVSS score of CVE-2026-74748?
CVE-2026-74748 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-74748?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-74748, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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