CVE-2026-74664net: openvswitch: reallocate update replies for mismatched IDs
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: net: openvswitch: reallocate update replies for mismatched IDs ovs_flow_cmd_new() preallocates the optional reply skb before it takes ovs_mutex and before it knows which existing flow will be updated. That is normally fine because the skb is sized from the request flow identifier. That identifier also becomes the inserted flow's identifier. For updates, however, a request with a UFID may miss the UFID lookup and then fall back to the flow key lookup. That lookup can legitimately find an existing key-identified flow. UFIDs are optional and the flow key is the primary identifier. For echoed replies, ovs_flow_cmd_fill_info() writes the matched flow's identifier, not the request identifier used for the preallocation. A short request UFID can therefore leave too little room for the key identifier. The fill can then fail with -EMSGSIZE and hit the BUG_ON(error < 0) in the update path. Once the update target has been resolved, reallocate the reply skb if the matched flow needs a larger reply than the request identifier allowed. Do this before replacing the actions so the request can still fail cleanly if the rare extra allocation fails.
- CVSS
- Not yet scored
- 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
- Aug 22, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 74ed7ab9264c54471c7f057409d352052820d750 before bd8ca84d48cd9a4f6fc63df26512c55e1d339927; 74ed7ab9264c54471c7f057409d352052820d750 builds before 00f987f066e802793a37dd2167459e67cf2cf2ec; from 74ed7ab9264c54471c7f057409d352052820d750 before 696a0b9435fce9cf4f1e9ba7f6afa6bee96c97fc; from 74ed7ab9264c54471c7f057409d352052820d750 before 87d0c0040b5d4b61de51ae39132c4c46709f2f77; 74ed7ab9264c54471c7f057409d352052820d750 builds before 69f40ccf85074981340847d650a9cbf9adabfbbe; from 74ed7ab9264c54471c7f057409d352052820d750 before 23716dd9d8d46a5908536b73dc085e62f2b5c237; from 74ed7ab9264c54471c7f057409d352052820d750 before 20751193d83be2e9735d4faee71375691c09cd13; 74ed7ab9264c54471c7f057409d352052820d750 builds before 5d1c224dd914579524a183a514c12b95095d12ce | CNA record |
References
- https://git.kernel.org/stable/c/bd8ca84d48cd9a4f6fc63df26512c55e1d339927
- https://git.kernel.org/stable/c/00f987f066e802793a37dd2167459e67cf2cf2ec
- https://git.kernel.org/stable/c/696a0b9435fce9cf4f1e9ba7f6afa6bee96c97fc
- https://git.kernel.org/stable/c/87d0c0040b5d4b61de51ae39132c4c46709f2f77
- https://git.kernel.org/stable/c/69f40ccf85074981340847d650a9cbf9adabfbbe
- https://git.kernel.org/stable/c/23716dd9d8d46a5908536b73dc085e62f2b5c237
- https://git.kernel.org/stable/c/20751193d83be2e9735d4faee71375691c09cd13
- https://git.kernel.org/stable/c/5d1c224dd914579524a183a514c12b95095d12ce
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.