CVE-2026-31393
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Validate L2CAP_INFO_RSP payload length before access l2cap_information_rsp() checks that cmd_len covers the fixed l2cap_info_rsp header (type + result, 4 bytes) but then reads rsp->data without verifying that the payload is present: - L2CAP_IT_FEAT_MASK calls get_unaligned_le32(rsp->data), which reads 4 bytes past the header (needs cmd_len >= 8). - L2CAP_IT_FIXED_CHAN reads rsp->data[0], 1 byte past the header (needs cmd_len >= 5). A truncated L2CAP_INFO_RSP with result == L2CAP_IR_SUCCESS triggers an out-of-bounds read of adjacent skb data. Guard each data access with the required payload length check. If the payload is too short, skip the read and let the state machine complete with safe defaults (feat_mask and remote_fixed_chan remain zero from kzalloc), so the info timer cleanup and l2cap_conn_start() still run and the connection is not stalled.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 6.1.170-1 |
| debian | bullseye | fixed | 6.1.170-1~deb11u1 |
| debian | forky | fixed | 6.19.10-1 |
| debian | sid | fixed | 6.19.10-1 |
| debian | trixie | fixed | 6.12.85-1 |
| linux-kernel | affected | 5.10.253 | |
| linux-kernel | 7.0 | affected | |
References
- https://git.kernel.org/stable/c/187e6fe939295be36063a1d91f8bebee04399a8c
- https://git.kernel.org/stable/c/3b646516cba2ebc4b51a72954903326e7c1e443f
- https://git.kernel.org/stable/c/5229e7d15771eac2b5886bfb1f976aea0c1eec14
- https://git.kernel.org/stable/c/807bd1258453c4c83f6ae9dbc1e7b44860ff40d0
- https://git.kernel.org/stable/c/9aeacde4da0f02d42fd968fd32f245828b230171
- https://git.kernel.org/stable/c/db2872d054e467810078e2b9f440a5b326a601b2
- https://git.kernel.org/stable/c/dd815e6e3918dc75a49aaabac36e4f024d675101
- https://git.kernel.org/stable/c/e7ff754e339e3d5ce29aa9f95352d0186df8fbd9
- https://www.suse.com/security/cve/CVE-2026-31393.html
- https://security-tracker.debian.org/tracker/CVE-2026-31393
CWEs
CWE-125
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.