# CVE-2026-31512: Bluetooth: L2CAP: Validate PDU length before reading SDU length in l2cap_ecred_data_rcv()

Status: published. Published: 2026-04-22. Updated: 2026-11-05.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linux / Linux: ≥ aac23bf636593cc2d67144aed373a46a1a5f76b1; < cef09691cfb61f6c91cc27c3d69634f81c8ab949 (affected, git); ≥ aac23bf636593cc2d67144aed373a46a1a5f76b1; < 3340be2bafdcc806f048273ea6d8e82a6597aa1b (affected, git); ≥ aac23bf636593cc2d67144aed373a46a1a5f76b1; < e47315b84d0eb188772c3ff5cf073cdbdefca6b4 (affected, git); ≥ aac23bf636593cc2d67144aed373a46a1a5f76b1; < 477ad4976072056c348937e94f24583321938df4 (affected, git); ≥ aac23bf636593cc2d67144aed373a46a1a5f76b1; < 40c7f7eea2f4d9cb0b3e924254c8c9053372168f (affected, git); ≥ aac23bf636593cc2d67144aed373a46a1a5f76b1; < 8c96f3bd4ae0802db90630be8e9851827e9c9209 (affected, git); ≥ aac23bf636593cc2d67144aed373a46a1a5f76b1; < 5ad981249be52f5e4e92e0e97b436b569071cb86 (affected, git); ≥ aac23bf636593cc2d67144aed373a46a1a5f76b1; < c65bd945d1c08c3db756821b6bf9f1c4a77b29c6 (affected, git). Source: CNA: Linux
- Linux / Linux: 3.14 (affected); ≥ 0; < 3.14 (unaffected, semver); ≥ 5.10.253; ≤ 5.10.* (unaffected, semver); ≥ 5.15.203; ≤ 5.15.* (unaffected, semver); ≥ 6.1.168; ≤ 6.1.* (unaffected, semver); ≥ 6.6.131; ≤ 6.6.* (unaffected, semver); ≥ 6.12.80; ≤ 6.12.* (unaffected, semver); ≥ 6.18.21; ≤ 6.18.* (unaffected, semver); ≥ 6.19.11; ≤ 6.19.* (unaffected, semver); ≥ 7.0; ≤ * (unaffected, original_commit_for_fix). Source: CNA: Linux

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: 0.12% as of 2026-11-05; percentile 2.03%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: Not reported

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://git.kernel.org/stable/c/cef09691cfb61f6c91cc27c3d69634f81c8ab949 (CNA: Linux)

- https://git.kernel.org/stable/c/3340be2bafdcc806f048273ea6d8e82a6597aa1b (CNA: Linux)

- https://git.kernel.org/stable/c/e47315b84d0eb188772c3ff5cf073cdbdefca6b4 (CNA: Linux)

- https://git.kernel.org/stable/c/477ad4976072056c348937e94f24583321938df4 (CNA: Linux)

- https://git.kernel.org/stable/c/40c7f7eea2f4d9cb0b3e924254c8c9053372168f (CNA: Linux)

- https://git.kernel.org/stable/c/8c96f3bd4ae0802db90630be8e9851827e9c9209 (CNA: Linux)

- https://git.kernel.org/stable/c/5ad981249be52f5e4e92e0e97b436b569071cb86 (CNA: Linux)

- https://git.kernel.org/stable/c/c65bd945d1c08c3db756821b6bf9f1c4a77b29c6 (CNA: Linux)

## Provenance

- CNA: Linux: https://www.cve.org/CVERecord?id=CVE-2026-31512; retrieved 2026-11-05; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-31512; retrieved 2026-11-05; source updated Not reported

Revision: 83a86bfde5bd9934b25e3950073f3548dc9143ac6adc7dc25b55c4ec4c2ddae7

Canonical: https://y2.dev/cve/CVE-2026-31512

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.