CVE-2026-90160lwt_bpf: Restore reserved headroom after xmit program
- —Not scoredno CVSS score yet
- 0.22%Exploitation in 30 daysEPSS · top 88% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: lwt_bpf: Restore reserved headroom after xmit program ip_finish_output2() expands an skb to LL_RESERVED_SPACE(dev) before LWT xmit. An LWT_XMIT BPF program can then modify the skb head and still return BPF_OK, so bpf_xmit() rechecks the remaining headroom before the skb continues to neighbour output. That recheck uses dst->dev->hard_header_len. This is not enough for the neighbour cached-header path: neigh_hh_output() copies the cached hardware header using the aligned hh_cache size, HH_DATA_MOD for short headers or HH_DATA_ALIGN(hh_len) otherwise. On Ethernet, hard_header_len is 14 but the cached copy needs 16 bytes. If an LWT_XMIT BPF program calls bpf_skb_change_head(skb, 1, 0), the skb can still have 15 bytes of headroom after the program. The existing check accepts that, after which neigh_hh_output() hits its headroom warning and drops the skb. Use LL_RESERVED_SPACE(dst->dev) in the post-BPF headroom check to match the reservation made before LWT xmit.
Timeline
ID reserved
By Linux
- 6 days later
· 6 days later
Published
- 32 days later
· 32 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.22% · top 88% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < 753e5cdcca5474d230d62bb3489e5168ab27c272
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < c488071c3441fa34f5a87cd6c12ce2cc6304f20e
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < a38c0eb447e2dd0120a2ebcdba470f9505ac8907
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < de2b2004e16f2930eb689175e2c1998b0a68d499
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < 7d043e24520a273c362be5dd7d9c82796879a49b
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < 7cf561843ed0ad57501892a65abb77957e6c800f
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < 179a5b2171573d94a25c9aa8e1c9f9ac352ad316
- affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 – < 5fe7007aed9ad069b2bd77e5d0c875c64f5c0269
- affected 4.10
- unaffected < 4.10
- unaffected 5.10.270 – ≤ 5.10.*
- unaffected 5.15.221 – ≤ 5.15.*
- unaffected 6.1.188 – ≤ 6.1.*
- unaffected 6.6.157 – ≤ 6.6.*
- unaffected 6.12.110 – ≤ 6.12.*
- unaffected 6.18.52 – ≤ 6.18.*
- unaffected 7.2.6 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References8
- https://git.kernel.org/stable/c/753e5cdcca5474d230d62bb3489e5168ab27c272 (opens in a new tab)
- https://git.kernel.org/stable/c/c488071c3441fa34f5a87cd6c12ce2cc6304f20e (opens in a new tab)
- https://git.kernel.org/stable/c/a38c0eb447e2dd0120a2ebcdba470f9505ac8907 (opens in a new tab)
- https://git.kernel.org/stable/c/de2b2004e16f2930eb689175e2c1998b0a68d499 (opens in a new tab)
- https://git.kernel.org/stable/c/7d043e24520a273c362be5dd7d9c82796879a49b (opens in a new tab)
- https://git.kernel.org/stable/c/7cf561843ed0ad57501892a65abb77957e6c800f (opens in a new tab)
- https://git.kernel.org/stable/c/179a5b2171573d94a25c9aa8e1c9f9ac352ad316 (opens in a new tab)
- https://git.kernel.org/stable/c/5fe7007aed9ad069b2bd77e5d0c875c64f5c0269 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-81753 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2026-90160)Record last updated .