cbcvebase.
CVE-2025-68775
published 2026-01-13

CVE-2025-68775: In the Linux kernel, the following vulnerability has been resolved: net/handshake: duplicate handshake cancellations leak socket When a handshake request is…

PriorityP354critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.55%
45.2th percentile
In the Linux kernel, the following vulnerability has been resolved: net/handshake: duplicate handshake cancellations leak socket When a handshake request is cancelled it is removed from the handshake_net->hn_requests list, but it is still present in the handshake_rhashtbl until it is destroyed. If a second cancellation request arrives for the same handshake request, then remove_pending() will return false... and assuming HANDSHAKE_F_REQ_COMPLETED isn't set in req->hr_flags, we'll continue processing through the out_true label, where we put another reference on the sock and a refcount underflow occurs. This can happen for example if a handshake times out - particularly if the SUNRPC client sends the AUTH_TLS probe to the server but doesn't follow it up with the ClientHello due to a problem with tlshd. When the timeout is hit on the server, the server will send a FIN, which triggers a cancellation request via xs_reset_transport(). When the timeout is hit on the client, another cancellation request happens via xs_tls_handshake_sync(). Add a test_and_set_bit(HANDSHAKE_F_REQ_COMPLETED) in the pending cancel path so duplicate cancels can be detected.

Affected

40 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.18.3-1 (forky)linux 6.18.3-1 (forky)
linuxlinux——
linuxlinux>= 3b3009ea8abb713b022d94fba95ec270cf6e7eae < 011ae80c49d9bfa5b4336f8bd387cd25c7593663011ae80c49d9bfa5b4336f8bd387cd25c7593663
linuxlinux>= 3b3009ea8abb713b022d94fba95ec270cf6e7eae < e1641177e7fb48a0a5a06658d4aab51da6656659e1641177e7fb48a0a5a06658d4aab51da6656659
linuxlinux>= 3b3009ea8abb713b022d94fba95ec270cf6e7eae < 3c330f1dee3cd92b57e19b9d21dc8ce5970b09be3c330f1dee3cd92b57e19b9d21dc8ce5970b09be
linuxlinux>= 3b3009ea8abb713b022d94fba95ec270cf6e7eae < 15564bd67e2975002f2a8e9defee33e321d3183f15564bd67e2975002f2a8e9defee33e321d3183f
linuxlinux_kernel>= 0 < 6.12.69-16.12.69-1
linuxlinux_kernel>= 0 < 6.18.3-16.18.3-1
linuxlinux_kernel>= 6.13.0 < 6.18.36.18.3
linuxlinux_kernel>= 6.4.0 < 6.6.1206.6.120
linuxlinux_kernel>= 6.7.0 < 6.12.646.12.64
ubuntulinux-aws——
ubuntulinux-aws-6.17——
ubuntulinux-aws-fips——
ubuntulinux-azure——
ubuntulinux-azure-6.17——
ubuntulinux-azure-6.8——
ubuntulinux-azure-fips——
ubuntulinux-fips——
ubuntulinux-gcp——
ubuntulinux-gcp-6.17——
ubuntulinux-gcp-6.8——
ubuntulinux-gcp-fips——
ubuntulinux-hwe-6.17——
ubuntulinux-hwe-6.8——

CVSS provenance

nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vendor_ubuntu6.4MEDIUM
vendor_redhat3.3LOW
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.