CVE-2026-98171

About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs

Fix several related bounds checking and pointer lifecycle issues in receive_encrypted_standard()’s handling of compound encrypted frames:

• Clear next_buffer after assigning it to server->bigbuf. A stale next_buffer pointer can lead to a use-after-free on subsequent error paths.
• Update pdu_length to the decrypted plaintext size (buf_size). Using the pre-decryption length allows NextCommand to point into stale ciphertext residue.
• Reject next_cmd values smaller than MID_HEADER_SIZE(server).
• Fix an integer overflow in the upper bound check by verifying pdu_length - next_cmd < MID_HEADER_SIZE(server), ensuring the trailing slice is large enough for a header.

Affected product:

AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 20.04 ELS

Affected packages:

linux @ 5.10.259 (+7 more)

Live-patch status from KernelCare for each operating system.