CVE-2026-68123openvswitch: fix GSO userspace truncation underflow
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: openvswitch: fix GSO userspace truncation underflow OVS_ACTION_ATTR_TRUNC currently stores a delta from the original skb length in OVS_CB(skb)->cutlen. When a later userspace action segments a GSO skb, queue_gso_packets() reuses that delta for each smaller segment. A segment can then reach queue_userspace_packet() with cutlen greater than skb->len, underflowing the length passed to skb_zerocopy(). Store the maximum preserved length instead and bound each consumer against the current skb length. Use U32_MAX as the no-truncation sentinel so the value remains valid if skb geometry changes before a consumer handles it.
- CVSS
- 9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 before 50a6a85f3d6b1d22d8436848606cdef5d2c490b4; from f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 before 2623c48cc3a8da9a1886fd8f65c0e348f4406fd6; from f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 before e211b081901ffca76674082c73eeaed53524c369; from f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 before a16eaaf7c0b0ccdef6166707d90ffbc6eebf6855; from f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 before fbfa3ad2ad6f3a5624aba5211c46290fb98cc9dc; from f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 before 100a23b1613e9218e0af654ef102352c713f0263; from f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 before ea85dbcbe8d4056ecb54352f97743d138ea4c407; from f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 before 4032f8ed10fcb84d41c508dfb04be96589f78dfe | CNA record |
References
- https://git.kernel.org/stable/c/50a6a85f3d6b1d22d8436848606cdef5d2c490b4
- https://git.kernel.org/stable/c/2623c48cc3a8da9a1886fd8f65c0e348f4406fd6
- https://git.kernel.org/stable/c/e211b081901ffca76674082c73eeaed53524c369
- https://git.kernel.org/stable/c/a16eaaf7c0b0ccdef6166707d90ffbc6eebf6855
- https://git.kernel.org/stable/c/fbfa3ad2ad6f3a5624aba5211c46290fb98cc9dc
- https://git.kernel.org/stable/c/100a23b1613e9218e0af654ef102352c713f0263
- https://git.kernel.org/stable/c/ea85dbcbe8d4056ecb54352f97743d138ea4c407
- https://git.kernel.org/stable/c/4032f8ed10fcb84d41c508dfb04be96589f78dfe
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.