CVE-2026-98171
Published: October 9, 2026Last modified: October 9, 2026
Description
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 8.8 |
| Attack Vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | REQUIRED |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.189-r0) |
| 25 LTS | linux-lts | Fixed (6.12.112-r0) | |
| Stream | linux-lts | Fixed (6.18.55-r0) |
References
- https://git.kernel.org/stable/c/05762c5bc1cfdcac36747994fde2c04387a457f1
- https://git.kernel.org/stable/c/491e33144dee872cffda207f6fcb09260728f803
- https://git.kernel.org/stable/c/72eaef1f37a3b6bec11c342736834dc3707be3e4
- https://git.kernel.org/stable/c/858d5ac22cb889266993e7670f9f0c4f4aeedd78
- https://git.kernel.org/stable/c/8749946579708ea0d339034bb7f423a67dbe89cf
- https://git.kernel.org/stable/c/96c436e4b010711452b2872558938f4ef276492a