CVE-2026-46273ibmveth: Disable GSO for packets with small MSS
- 8.6HighCVSS base score
- 0.39%Exploitation in 30 daysEPSS · top 66% 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: ibmveth: Disable GSO for packets with small MSS Some physical adapters on Power systems do not support segmentation offload when the MSS is less than 224 bytes. Attempting to send such packets causes the adapter to freeze, stopping all traffic until manually reset. Implement ndo_features_check to disable GSO for packets with small MSS values. The network stack will perform software segmentation instead. The 224-byte minimum matches ibmvnic commit <f10b09ef687f> ("ibmvnic: Enforce stronger sanity checks on GSO packets") which uses the same physical adapters in SEA configurations. The issue occurs specifically when the hardware attempts to perform segmentation (gso_segs > 1) with a small MSS. Single-segment GSO packets (gso_segs == 1) do not trigger the problematic LSO code path and are transmitted normally without segmentation. Add an ndo_features_check callback to disable GSO when MSS < 224 bytes. Also call vlan_features_check() to ensure proper handling of VLAN packets, particularly QinQ (802.1ad) configurations where the hardware parser may not support certain offload features. Validated using iptables to force small MSS values. Without the fix, the adapter freezes. With the fix, packets are segmented in software and transmission succeeds. Comprehensive regression testing completedd (MSS tests, performance, stability).
Timeline
ID reserved
By Linux
- 21 days later
· 21 days later
Published
- 2 months later
· 2 months 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
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High8.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High8.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.39% · top 66% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.6.
Affected products
- affected 8641dd85799f85bef5f0d1f87356aaa12cb2195e – < 86fc64584811d43c9ccd74447de58620189d8b77
- affected 8641dd85799f85bef5f0d1f87356aaa12cb2195e – < 9a5e984d7af910e46dcbed3ce77873e000a4f77d
- affected 8641dd85799f85bef5f0d1f87356aaa12cb2195e – < 1cdf5dbcec988d06f5f720bdf89e91073f77fa10
- affected 8641dd85799f85bef5f0d1f87356aaa12cb2195e – < 82bc89fbb82d9396fb4eaee8720ea85e2e787957
- affected 8641dd85799f85bef5f0d1f87356aaa12cb2195e – < db8012c631cb845e9ae2b4b531e17d86c9519755
- affected 8641dd85799f85bef5f0d1f87356aaa12cb2195e – < c1f261863e65b508f37416dfbc5c5d911c9b9233
- affected 8641dd85799f85bef5f0d1f87356aaa12cb2195e – < 3af24f0c4c31f18a4a2d927990759194832bb6e9
- affected 8641dd85799f85bef5f0d1f87356aaa12cb2195e – < cc427d24ac6442ffdeafd157a63c7c5b73ed4de4
- affected 4.2
- unaffected < 4.2
- unaffected 5.10.258 – ≤ 5.10.*
- unaffected 5.15.209 – ≤ 5.15.*
- unaffected 6.1.175 – ≤ 6.1.*
- unaffected 6.6.140 – ≤ 6.6.*
- unaffected 6.12.88 – ≤ 6.12.*
- unaffected 6.18.30 – ≤ 6.18.*
- unaffected 7.0.7 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References8
- https://git.kernel.org/stable/c/86fc64584811d43c9ccd74447de58620189d8b77 (opens in a new tab)
- https://git.kernel.org/stable/c/9a5e984d7af910e46dcbed3ce77873e000a4f77d (opens in a new tab)
- https://git.kernel.org/stable/c/1cdf5dbcec988d06f5f720bdf89e91073f77fa10 (opens in a new tab)
- https://git.kernel.org/stable/c/82bc89fbb82d9396fb4eaee8720ea85e2e787957 (opens in a new tab)
- https://git.kernel.org/stable/c/db8012c631cb845e9ae2b4b531e17d86c9519755 (opens in a new tab)
- https://git.kernel.org/stable/c/c1f261863e65b508f37416dfbc5c5d911c9b9233 (opens in a new tab)
- https://git.kernel.org/stable/c/3af24f0c4c31f18a4a2d927990759194832bb6e9 (opens in a new tab)
- https://git.kernel.org/stable/c/cc427d24ac6442ffdeafd157a63c7c5b73ed4de4 (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-2026-34138 (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)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-46273)Record last updated .