CVE-2026-74480

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-15. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 5 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: 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:

net: bridge: stop fast-leave after deleting a port group

br_multicast_leave_group() iterates mp->ports with pp = &p->next in its fast-leave path. After br_multicast_del_pg() removes p, continuing the loop advances pp through the deleted entry.

If multicast-to-unicast was enabled, the bridge can hold multiple port groups for the same port and group with different source MAC addresses. Once multicast-to-unicast is disabled, br_port_group_equal() matches those entries by port only. A fast leave can then delete one entry and continue from its stale next pointer, leaving mp->ports pointing at a deleted port group.

Fast leave only needs to remove one matching port group. Break after br_multicast_del_pg() so the loop stops before dereferencing the removed entry.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
38%
KEV
Not listed

Published

August 15, 2026

Last Modified

August 19, 2026

Advisory Details (8)

Auto-updated Aug 19, 2026
No patch confirmed yet.
generic

net: bridge: stop fast-leave after deleting a port group - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d6c32e2e25a9a06ba021030e26b6d602a277eb72
generic

net: bridge: stop fast-leave after deleting a port group - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a39789f211b8a4125f0c70e05b30cf715f4f187d
generic

net: bridge: stop fast-leave after deleting a port group - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4c57056ca6aace2e9f94ae9298bf49ef6b0c95e4
generic

net: bridge: stop fast-leave after deleting a port group - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/482bcb85139addb4e8ac8ed10baeda3e0aad4031
generic

net: bridge: stop fast-leave after deleting a port group - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4695430e8132420bf8de94da3eb36a6cf35fde6b
generic

net: bridge: stop fast-leave after deleting a port group - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1a109cc9890d017c41d77e6c82da739579c49f0b
generic

net: bridge: stop fast-leave after deleting a port group - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/159ad90cb929c033308bb39a2c5f8fbf393b77aa
generic

net: bridge: stop fast-leave after deleting a port group - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0309ebbc570000ea0df11c06b69798e5860c5f6f

Vendor Advisories for CVE-2026-74480(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 42× in last 7d / 42× 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. 2026-08-20 15:07 UTCGHSA enrichment
  2. 2026-08-20 10:49 UTCGHSA enrichment
  3. 2026-08-20 06:32 UTCGHSA enrichment
  4. 2026-08-20 02:14 UTCGHSA enrichment
  5. 2026-08-19 21:55 UTCGHSA enrichment
  6. 2026-08-19 17:36 UTCEG score recompute
  7. 2026-08-19 17:35 UTCGHSA enrichment
  8. 2026-08-19 17:04 UTCEPSS rescore
  9. 2026-08-19 16:45 UTCEG score recompute
  10. 2026-08-19 16:45 UTCGHSA enrichment
  11. 2026-08-19 14:58 UTCGHSA enrichment
  12. 2026-08-19 10:40 UTCGHSA enrichment
  13. 2026-08-19 06:19 UTCGHSA enrichment
  14. 2026-08-19 01:54 UTCGHSA enrichment
  15. 2026-08-18 21:37 UTCGHSA enrichment
  16. 2026-08-18 16:59 UTCEG score recompute
  17. 2026-08-18 16:59 UTCGHSA enrichment
  18. 2026-08-18 13:49 UTCEPSS rescore
  19. 2026-08-18 13:49 UTCEPSS rescore
  20. 2026-08-18 12:40 UTCGHSA enrichment
  21. 2026-08-18 08:16 UTCGHSA enrichment
  22. 2026-08-18 03:53 UTCGHSA enrichment
  23. 2026-08-17 23:36 UTCGHSA enrichment
  24. 2026-08-17 19:18 UTCGHSA enrichment
  25. 2026-08-17 15:00 UTCEG score recompute
Show 17 more
  1. 2026-08-17 15:00 UTCGHSA enrichment
  2. 2026-08-17 13:47 UTCEPSS rescore
  3. 2026-08-17 10:42 UTCEG score recompute
  4. 2026-08-17 10:42 UTCGHSA enrichment
  5. 2026-08-17 06:24 UTCEG score recompute
  6. 2026-08-17 06:24 UTCGHSA enrichment
  7. 2026-08-17 05:55 UTCEG score recompute▲ 9.80
  8. 2026-08-17 05:55 UTCGHSA enrichment
  9. 2026-08-17 05:54 UTCMITRE cvelistV5CVSS v3 → 9.8 · severity → CRITICAL
  10. 2026-08-17 05:25 UTCEG score recompute
  11. 2026-08-17 05:25 UTCGHSA enrichment
  12. 2026-08-17 05:24 UTCMITRE cvelistV5
  13. 2026-08-16 14:56 UTCEPSS rescore
  14. 2026-08-16 14:56 UTCEPSS rescore
  15. 2026-08-15 13:27 UTCNVD update
  16. 2026-08-15 12:40 UTCEG score recompute
  17. 2026-08-15 12:37 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-74480?
CVE-2026-74480 is a critical vulnerability published on August 15, 2026. In the Linux kernel, the following vulnerability has been resolved: net: bridge: stop fast-leave after deleting a port group brmulticastleave_group() iterates mp->ports with pp = &p->next in its fast-leave path. After brmulticastdel_pg() removes p, continuing the loop advances pp through the…
When was CVE-2026-74480 disclosed?
CVE-2026-74480 was first published in the National Vulnerability Database on August 15, 2026, with the most recent update on August 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-74480 actively exploited?
CVE-2026-74480 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 61.9% of all scored CVEs.
What is the CVSS score of CVE-2026-74480?
CVE-2026-74480 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-74480?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-74480, 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.

Dependency Blast Radius

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