CVE-2026-74597

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-22. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 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: 1%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:

ip6_tunnel: clear skb2->cb[] in ip6ip6_err()

ip6ip6_err() clones an outer IPv6 ICMP error skb, pulls it to the quoted inner IPv6 packet, and then passes the clone to icmpv6_send(). The clone still carries the outer packet's inet6_skb_parm in skb->cb.

If the outer packet had a Home Address Option, IP6CB(skb2)->dsthao remains non-zero after skb_pull(). icmpv6_send() later calls mip6_addr_swap(), which uses that stale dsthao offset against the quoted inner packet. A malformed inner destination-options header can then make the HAO lookup and address swap run past the end of the quoted packet and corrupt skb_shared_info.

Clear skb2->cb[] before pulling the quoted inner IPv6 packet so the reply path does not reuse metadata left by the outer IPv6 stack.

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%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
42%
KEV
Not listed

Published

August 22, 2026

Last Modified

August 25, 2026

Advisory Details (8)

Auto-updated Aug 25, 2026
No patch confirmed yet.
generic

ip6_tunnel: clear skb2->cb[] in ip6ip6_err() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/fbf40faa0414b753212494ad197542002e66ed9e
generic

ip6_tunnel: clear skb2->cb[] in ip6ip6_err() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f803c086399da277b5d0ff36a107d0f162751800
generic

ip6_tunnel: clear skb2->cb[] in ip6ip6_err() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b6816536a2990c0db44a26130a03e40b441e829b
generic

ip6_tunnel: clear skb2->cb[] in ip6ip6_err() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/64e41736a26f37ab6215bc2e6df125df05aceb08
generic

ip6_tunnel: clear skb2->cb[] in ip6ip6_err() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4eb15c465337b18f44716c499cd6ad63eee0ad54
generic

ip6_tunnel: clear skb2->cb[] in ip6ip6_err() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/484134e1eb07d700a73b1e4bbf3fb503e299be60
generic

ip6_tunnel: clear skb2->cb[] in ip6ip6_err() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/44fe898df302e91c5ee5acbc71ffa74e78e6c183
generic

ip6_tunnel: clear skb2->cb[] in ip6ip6_err() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0dadb0620ab65949a8bc2439dd28ea3c942fe87d

Vendor Advisories for CVE-2026-74597(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 46× in last 7d / 49× 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 05:08 UTCEG score recompute
  2. 2026-08-30 05:08 UTCGHSA enrichment
  3. 2026-08-30 01:22 UTCEPSS rescore
  4. 2026-08-30 01:17 UTCGHSA enrichment
  5. 2026-08-29 21:26 UTCGHSA enrichment
  6. 2026-08-29 17:36 UTCGHSA enrichment
  7. 2026-08-29 12:38 UTCGHSA enrichment
  8. 2026-08-29 08:44 UTCGHSA enrichment
  9. 2026-08-29 04:50 UTCGHSA enrichment
  10. 2026-08-29 00:59 UTCEG score recompute
  11. 2026-08-29 00:58 UTCGHSA enrichment
  12. 2026-08-28 21:42 UTCEPSS rescore
  13. 2026-08-28 17:34 UTCGHSA enrichment
  14. 2026-08-28 13:33 UTCGHSA enrichment
  15. 2026-08-28 09:42 UTCGHSA enrichment
  16. 2026-08-28 05:49 UTCGHSA enrichment
  17. 2026-08-28 01:57 UTCGHSA enrichment
  18. 2026-08-27 22:07 UTCGHSA enrichment
  19. 2026-08-27 18:16 UTCEG score recompute
  20. 2026-08-27 18:16 UTCGHSA enrichment
  21. 2026-08-27 14:25 UTCEPSS rescore
  22. 2026-08-27 13:12 UTCGHSA enrichment
  23. 2026-08-27 09:21 UTCGHSA enrichment
  24. 2026-08-27 05:29 UTCGHSA enrichment
  25. 2026-08-27 01:35 UTCGHSA enrichment
Show 24 more
  1. 2026-08-26 21:44 UTCGHSA enrichment
  2. 2026-08-26 17:52 UTCEG score recompute
  3. 2026-08-26 17:51 UTCGHSA enrichment
  4. 2026-08-26 14:47 UTCEPSS rescore
  5. 2026-08-26 13:22 UTCGHSA enrichment
  6. 2026-08-26 09:29 UTCGHSA enrichment
  7. 2026-08-26 05:39 UTCGHSA enrichment
  8. 2026-08-26 01:48 UTCGHSA enrichment
  9. 2026-08-25 21:58 UTCGHSA enrichment
  10. 2026-08-25 18:07 UTCGHSA enrichment
  11. 2026-08-25 14:13 UTCEG score recompute
  12. 2026-08-25 14:13 UTCGHSA enrichment
  13. 2026-08-25 13:49 UTCEPSS rescore
  14. 2026-08-25 10:20 UTCEG score recompute
  15. 2026-08-25 10:20 UTCGHSA enrichment
  16. 2026-08-25 06:30 UTCEG score recompute
  17. 2026-08-25 06:30 UTCGHSA enrichment
  18. 2026-08-25 05:45 UTCEG score recompute▲ 9.80
  19. 2026-08-25 05:45 UTCGHSA enrichment
  20. 2026-08-25 05:45 UTCMITRE cvelistV5CVSS v3 → 9.8 · severity → CRITICAL
  21. 2026-08-24 14:18 UTCEPSS rescore
  22. 2026-08-22 16:24 UTCNVD update
  23. 2026-08-22 15:42 UTCEG score recompute
  24. 2026-08-22 15:35 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-74597?
CVE-2026-74597 is a critical vulnerability published on August 22, 2026. In the Linux kernel, the following vulnerability has been resolved: ip6tunnel: clear skb2->cb[] in ip6ip6err() ip6ip6_err() clones an outer IPv6 ICMP error skb, pulls it to the quoted inner IPv6 packet, and then passes the clone to icmpv6_send(). The clone still carries the outer packet's…
When was CVE-2026-74597 disclosed?
CVE-2026-74597 was first published in the National Vulnerability Database on August 22, 2026, with the most recent update on August 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-74597 actively exploited?
CVE-2026-74597 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 58.4% of all scored CVEs.
What is the CVSS score of CVE-2026-74597?
CVE-2026-74597 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-74597?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-74597, 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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