In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: conntrack: fix helper UAF due to…
Linux · Linux
A use-after-free flaw in the Linux kernel's openvswitch connection tracking code (net/openvswitch conntrack) arises because helpers are invoked before all extensions are added, so a raw pointer to the extension area can be left dangling in the expectations list after the area is reallocated. An attacker with network access and no privileges or user interaction can trigger this by sending traffic that causes helper processing on an unconfirmed connection while further extensions are added, leading to memory corruption when the stale expectation is later accessed.
In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: conntrack: fix helper UAF due to extensions realloc While calling the helpers, a raw pointer to the extensions area is wired into expectations list: -> nf_ct_helper() -> helper->help() -> nf_ct_expect_related_report() -> nf_ct_expect_insert() -> hlist_add_head_rcu(&exp->lnode, &master_help->expectations) In case the connection is not confirmed yet, more extensions can be added afterwards with *_ext_add() calls reallocating the extension space and leaving the now invalid pointer in the expectations list that is later accessed while removing the expectation. Make sure that helpers are called at the end after all the other extensions are already added. Note that the helper rejection now leaves the mark and labels set, but that's not different from how the NAT was handled before or how the mark and the labels were handled on confirmation failure. And there are no atomicity guarantees provided by the API anyway.
- Exploited
- Not confirmed
- Reports
- 0
- Tactics
- 0/15
Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
Disclosed on 18 Oct 2026. No public exploit code or confirmed exploitation is recorded.
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
No techniques linkedNo ATT&CK techniques are linked to this CVE yet. MITRE CTID has not mapped it, and no report passage in the corpus ties it to a technique.
What security researchers reported
Not named in any threat report yetAlso mentioned in 4 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Known_Cve | Oct 27, 2026 | Part 1/326 Oct 2026
- Known_Cve | Oct 24, 2026 | Part 1/323 Oct 2026
- Known_Cve | Oct 23, 2026 | Part 2/322 Oct 2026
- Known_Cve | Oct 22, 2026 | Part 3/421 Oct 2026