macvlan: inherit needed_headroom and needed_tailroom from lowerdev
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.
- Published
- Aug 26, 2026
- Updated
- Oct 3, 2026
- EPSS
- 0.7% · 52th percentile
- CWE
- —
Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.
Report tools
Action score
39
Monitor
Low priority for now.
- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.7%
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 9.8
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 2.6.23affected
- b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 and later · before c2ef3f134b069c54b9cc95cce1a16c38c4939336affected · git
- b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 and later · before 7b0eb3e0f363ca79a3af9efd2e87c6258f11da2baffected · git
- b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 and later · before 8cd90e850e434577bf6774778657d26d6995e53faffected · git
- b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 and later · before 28afc87bd8da0b3348bbbd834c8a89e83712cf5eaffected · git
- b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 and later · before 8f6a05dbac05725e0786701eb04778c5bdbe4eaaaffected · git
- b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 and later · before 96fa90b74385b7f2b0d97251dd43d5ee6ca44668affected · git
- b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 and later · before bc9a00fb78e32bccc39d763bfd13a450705bac5daffected · git
- b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 and later · before cef51860becd9700217c81732ca1eb1ea6ed6fe1affected · git
- before 2.6.23not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.1.187-1 | 6.1.187-1 |
| Debian:12 | linux-6.12 | before 6.12.107-1~deb12u1 | 6.12.107-1~deb12u1 |
| Debian:13 | linux | before 6.12.105-1 | 6.12.105-1 |
| Debian:14 | linux | before 7.1.10-1 | 7.1.10-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
- CVE-2026-74309vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler40Plan
- CVE-2026-74280crypto: marvell/octeontx - fix DMA cleanup using wrong loop index40Plan
- CVE-2026-74279crypto: cavium/cpt - fix DMA cleanup using wrong loop index40Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 28afc87bd8da0b3348bbbd834c8a89e83712cf5e | Vendor (CNA) |
| Linux Linux | 7b0eb3e0f363ca79a3af9efd2e87c6258f11da2b | Vendor (CNA) |
| Linux Linux | 8cd90e850e434577bf6774778657d26d6995e53f | Vendor (CNA) |
| Linux Linux | 8f6a05dbac05725e0786701eb04778c5bdbe4eaa | Vendor (CNA) |
| Linux Linux | 96fa90b74385b7f2b0d97251dd43d5ee6ca44668 | Vendor (CNA) |
| Linux Linux | bc9a00fb78e32bccc39d763bfd13a450705bac5d | Vendor (CNA) |
| Linux Linux | c2ef3f134b069c54b9cc95cce1a16c38c4939336 | Vendor (CNA) |
| Linux Linux | cef51860becd9700217c81732ca1eb1ea6ed6fe1 | Vendor (CNA) |
| azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 | 6.6.157.1-1 · Release Notes | Microsoft (MSRC) |
| debian:linux | 6.1.187-1 · Debian:12 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.107-1~deb12u1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0919 · Aug 27, 2026(Linux Kernel Güvenlik Bildirimi)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
—
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.kernel.org/stable/c/28afc87bd8da0b3348bbbd834c8a89e83712cf5e
- git.kernel.org/stable/c/7b0eb3e0f363ca79a3af9efd2e87c6258f11da2b
- git.kernel.org/stable/c/8cd90e850e434577bf6774778657d26d6995e53f
- git.kernel.org/stable/c/8f6a05dbac05725e0786701eb04778c5bdbe4eaa
- git.kernel.org/stable/c/96fa90b74385b7f2b0d97251dd43d5ee6ca44668
- git.kernel.org/stable/c/bc9a00fb78e32bccc39d763bfd13a450705bac5d
- git.kernel.org/stable/c/c2ef3f134b069c54b9cc95cce1a16c38c4939336
- git.kernel.org/stable/c/cef51860becd9700217c81732ca1eb1ea6ed6fe1
Vendor advisories and official records. Exploit/PoC links are deliberately left out.