9.8

CVE-2026-74743: linux

CVSS: 9.8v3.1CriticalReceived
AliasesUBUNTU-CVE-2026-74743DEBIAN-CVE-2026-74743
Published 26-08-2026Last modified 16-10-2026
Open JSON

Vulnerability summary

CVE-2026-74743 is a critical (CVSS 9.8) vulnerability in linux. EPSS estimates a 0.54% chance of exploitation in the next 30 days, higher than 44.3% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.54%
0%100%
Low · +0.02 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 18 · Related 17
MGASA-2026-0506OPENSUSE-SU-2026:21910-1SUSE-SU-2026:23881-1SUSE-SU-2026:23887-1SUSE-SU-2026:23897-1SUSE-SU-2026:23902-1

Timeline

  1. 26-08-2026
    PublishedVulnerability first disclosed.
  2. 16-10-2026
    Last modifiedVulnerability information updated.

Description

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: 1. Inheriting needed_headroom and needed_tailroom from lowerdev in macvlan_init(). 2. Propagating needed_headroom and needed_tailroom updates to attached macvlans in macvlan_device_event() when receiving NETDEV_FEAT_CHANGE events.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.54%

Chance of exploitation in the next 30 days

Percentile

44%

Versus all other CVEs

30-day change

+0.02 pp

From 0.52% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.54%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Ubuntu169 products
  • linuxAll versions (No fix recorded)
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian2 products
  • linux< 6.1.187-1 | < 6.12.105-1 | < 7.1.10-1
  • linux-6.12< 6.12.107-1~deb12u1
Linux1 product
  • linux≥ b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53, < c2ef3f134b069c54b9cc95cce1a16c38c4939336 | ≥ b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53, < 7b0eb3e0f363ca79a3af9efd2e87c6258f11da2b | ≥ b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53, < 8cd90e850e434577bf6774778657d26d6995e53f | ≥ b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53, < 28afc87bd8da0b3348bbbd834c8a89e83712cf5e | ≥ b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53, < 8f6a05dbac05725e0786701eb04778c5bdbe4eaa | ≥ b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53, < 96fa90b74385b7f2b0d97251dd43d5ee6ca44668 | ≥ b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53, < bc9a00fb78e32bccc39d763bfd13a450705bac5d | ≥ b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53, < cef51860becd9700217c81732ca1eb1ea6ed6fe1 | 2.6.23

3 vendors · 172 products

References

13 links
Show all 13 references