CVE-2026-74664
net: openvswitch: reallocate update replies for mismatched IDs
Description
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.
INFO
Published Date :
Aug. 22, 2026, 4:16 p.m.
Last Modified :
Aug. 22, 2026, 4:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-74664
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Reallocate the reply skb before replacing actions.
- Ensure flow identifiers are handled correctly.
- Apply vendor-provided updates and patches.
- Test changes thoroughly before deployment.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-74664.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74664 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-74664
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-74664 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74664 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 22, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '74ed7ab9264c54471c7f057409d352052820d750', 'lessThan': 'bd8ca84d48cd9a4f6fc63df26512c55e1d339927', 'versionType': 'git'}, {'status': 'affected', 'version': '74ed7ab9264c54471c7f057409d352052820d750', 'lessThan': '00f987f066e802793a37dd2167459e67cf2cf2ec', 'versionType': 'git'}, {'status': 'affected', 'version': '74ed7ab9264c54471c7f057409d352052820d750', 'lessThan': '696a0b9435fce9cf4f1e9ba7f6afa6bee96c97fc', 'versionType': 'git'}, {'status': 'affected', 'version': '74ed7ab9264c54471c7f057409d352052820d750', 'lessThan': '87d0c0040b5d4b61de51ae39132c4c46709f2f77', 'versionType': 'git'}, {'status': 'affected', 'version': '74ed7ab9264c54471c7f057409d352052820d750', 'lessThan': '69f40ccf85074981340847d650a9cbf9adabfbbe', 'versionType': 'git'}, {'status': 'affected', 'version': '74ed7ab9264c54471c7f057409d352052820d750', 'lessThan': '23716dd9d8d46a5908536b73dc085e62f2b5c237', 'versionType': 'git'}, {'status': 'affected', 'version': '74ed7ab9264c54471c7f057409d352052820d750', 'lessThan': '20751193d83be2e9735d4faee71375691c09cd13', 'versionType': 'git'}, {'status': 'affected', 'version': '74ed7ab9264c54471c7f057409d352052820d750', 'lessThan': '5d1c224dd914579524a183a514c12b95095d12ce', 'versionType': 'git'}], 'programFiles': ['net/openvswitch/datapath.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.0'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.265', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.216', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.183', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.152', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.104', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.45', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.9', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/openvswitch/datapath.c'], 'defaultStatus': 'affected'}] Added Description 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. Added Reference https://git.kernel.org/stable/c/00f987f066e802793a37dd2167459e67cf2cf2ec Added Reference https://git.kernel.org/stable/c/20751193d83be2e9735d4faee71375691c09cd13 Added Reference https://git.kernel.org/stable/c/23716dd9d8d46a5908536b73dc085e62f2b5c237 Added Reference https://git.kernel.org/stable/c/5d1c224dd914579524a183a514c12b95095d12ce Added Reference https://git.kernel.org/stable/c/696a0b9435fce9cf4f1e9ba7f6afa6bee96c97fc Added Reference https://git.kernel.org/stable/c/69f40ccf85074981340847d650a9cbf9adabfbbe Added Reference https://git.kernel.org/stable/c/87d0c0040b5d4b61de51ae39132c4c46709f2f77 Added Reference https://git.kernel.org/stable/c/bd8ca84d48cd9a4f6fc63df26512c55e1d339927