CVE-2026-74743

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-27. 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: 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:

macvlan: inherit needed_headroom and needed_tailroom from lowerdev

macvlan devices inherit hard_header_len from lowerdev during macvlan_init(), but leave needed_headroom and needed_tailroom set to 0.

When the underlying lowerdev requires extra headroom or tailroom for headers/trailers (e.g. macsec, ipsec, wireguard, tunnels, or veth with rx headroom), upper layers calculating packet headroom and tailroom fail to reserve sufficient space.

This can result in reallocation overhead, skb headroom underflows, or KASAN slab-use-after-free crashes when dev_hard_header() / macvlan_hard_header() prepends header data or when lower devices append tailroom.

Fix this by:

  • Inheriting needed_headroom and needed_tailroom from lowerdev in macvlan_init().
  • Propagating needed_headroom and needed_tailroom updates to attached macvlans
in macvlan_device_event() when receiving NETDEV_FEAT_CHANGE events.

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 26, 2026

Last Modified

August 27, 2026

Advisory Details (6)

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

macvlan: inherit needed_headroom and needed_tailroom from lowerdev - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/cef51860becd9700217c81732ca1eb1ea6ed6fe1
generic

macvlan: inherit needed_headroom and needed_tailroom from lowerdev - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/bc9a00fb78e32bccc39d763bfd13a450705bac5d
generic

macvlan: inherit needed_headroom and needed_tailroom from lowerdev - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/96fa90b74385b7f2b0d97251dd43d5ee6ca44668
generic

macvlan: inherit needed_headroom and needed_tailroom from lowerdev - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8f6a05dbac05725e0786701eb04778c5bdbe4eaa
generic

macvlan: inherit needed_headroom and needed_tailroom from lowerdev - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8cd90e850e434577bf6774778657d26d6995e53f
generic

macvlan: inherit needed_headroom and needed_tailroom from lowerdev - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/28afc87bd8da0b3348bbbd834c8a89e83712cf5e

Vendor Advisories for CVE-2026-74743(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 30× in last 7d / 30× 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 05:52 UTCGHSA enrichment
  2. 2026-08-30 02:09 UTCEG score recompute
  3. 2026-08-30 02:09 UTCGHSA enrichment
  4. 2026-08-30 01:22 UTCEPSS rescore
  5. 2026-08-29 22:26 UTCGHSA enrichment
  6. 2026-08-29 18:45 UTCGHSA enrichment
  7. 2026-08-29 15:00 UTCGHSA enrichment
  8. 2026-08-29 11:17 UTCGHSA enrichment
  9. 2026-08-29 07:28 UTCGHSA enrichment
  10. 2026-08-29 03:41 UTCGHSA enrichment
  11. 2026-08-28 23:58 UTCEG score recompute
  12. 2026-08-28 23:58 UTCGHSA enrichment
  13. 2026-08-28 21:42 UTCEPSS rescore
  14. 2026-08-28 16:29 UTCGHSA enrichment
  15. 2026-08-28 12:46 UTCGHSA enrichment
  16. 2026-08-28 09:01 UTCGHSA enrichment
  17. 2026-08-28 05:16 UTCGHSA enrichment
  18. 2026-08-28 01:30 UTCGHSA enrichment
  19. 2026-08-27 21:48 UTCGHSA enrichment
  20. 2026-08-27 18:06 UTCEG score recompute
  21. 2026-08-27 18:06 UTCGHSA enrichment
  22. 2026-08-27 14:25 UTCEPSS rescore
  23. 2026-08-27 13:49 UTCGHSA enrichment
  24. 2026-08-27 10:07 UTCEG score recompute
  25. 2026-08-27 10:06 UTCGHSA enrichment
Show 5 more
  1. 2026-08-27 06:22 UTCEG score recompute▲ 9.80
  2. 2026-08-27 06:11 UTCMITRE cvelistV5CVSS v3 → 9.8 · severity → CRITICAL
  3. 2026-08-26 15:43 UTCNVD update
  4. 2026-08-26 14:44 UTCEG score recompute
  5. 2026-08-26 14:41 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-74743?
CVE-2026-74743 is a critical vulnerability published on August 26, 2026. In the Linux kernel, the following vulnerability has been resolved: macvlan: inherit neededheadroom and neededtailroom from lowerdev macvlan devices inherit hardheaderlen from lowerdev during macvlan_init(), but leave neededheadroom and neededtailroom set to 0. When the underlying lowerdev requires…
When was CVE-2026-74743 disclosed?
CVE-2026-74743 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-2026-74743 actively exploited?
CVE-2026-74743 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 58.1% of all scored CVEs.
What is the CVSS score of CVE-2026-74743?
CVE-2026-74743 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-74743?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-74743, 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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