CVE-2026-53389: In the Linux kernel, the following vulnerability has been resolved: net/tcp-ao: fix use-after-free of key in del_async path In tcp_ao_delete_key(), the del_async path skips the c

highCVSS 7.8CVE-2026-53389

In the Linux kernel, the following vulnerability has been resolved: net/tcp-ao: fix use-after-free of key in del_async path In tcp_ao_delete_key(), the del_async path skips the current_key and rnext_key validity checks present in the synchronous path, assuming these pointers are always NULL on LISTEN sockets. However, if a key was added with set_current=1/set_rnext=1 while the socket was in CLOSE state, current_key and rnext_key will be non-NULL after listen() transitions the socket to LISTEN. When such a key is deleted with del_async=1, hlist_del_rcu() and call_rcu() free the key without clearing the dangling pointers. After the RCU grace period, getsockopt(TCP_AO_INFO) dereferences current_key->sndid and rnext_key->rcvid from freed slab memory. Clear current_key and rnext_key in the del_async path when they reference the key being deleted.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: high — CVSS 7.8
Published: 2026-07-19
Last updated: 2026-07-20
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-53389

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-533890.13% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 3% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-53389	coverage & exploitation status	NVD · CVE.org

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