# Bluetooth: l2cap: Check encryption key size on incoming connection

CVE record · `CVE-2025-39889`

- **Identifiers:** `CVE-2025-39889`
- **State:** Confirmed
- **Severity:** CVSS 8.1 High
- **Critical:** No
- **CNA:** Linux
- **Weakness (CWE):** [CWE-326](https://cwe.mitre.org/data/definitions/326.html)
- **Tags:** [Weak cryptography or TLS](https://agentprime.io/advisories/tag/weak-crypto.md)
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 24 Sept 2025
- **Updated:** 5 Aug 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 24 Sept 2025, 11:02 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `4f911a538e089cce808a15dc3277250f4f8daef9 to before ed503d340a501e414114ddc614a3aae4f6e9eae2` (git)
  - affected: `288c06973daae4637f25a0d1bdaf65fdbf8455f9 to before 24b2cdfc16e9bd6ab3d03b8e01c590755bd3141f` (git)
  - affected: `288c06973daae4637f25a0d1bdaf65fdbf8455f9 to before c6d527bbd3d3896375079f5dbc8b7f96734a3ba5` (git)
  - affected: `288c06973daae4637f25a0d1bdaf65fdbf8455f9 to before 9e3114958d87ea88383cbbf38c89e04b8ea1bce5` (git)
  - affected: `288c06973daae4637f25a0d1bdaf65fdbf8455f9 to before d49798ecd26e0ee7995a7fc1e90ca5cd9b4402d6` (git)
  - affected: `288c06973daae4637f25a0d1bdaf65fdbf8455f9 to before d4ca2fd218caafbf50e3343ba1260c6a23b5676a` (git)
  - affected: `288c06973daae4637f25a0d1bdaf65fdbf8455f9 to before 522e9ed157e3c21b4dd623c79967f72c21e45b78` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `5.11`
  - unaffected: `before 5.11` (semver)
  - unaffected: `5.15.181 to 5.15.*, inclusive` (semver)
  - unaffected: `6.1.135 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.88 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.25 to 6.12.*, inclusive` (semver)
  - unaffected: `6.14.4 to 6.14.*, inclusive` (semver)
  - unaffected: `6.15 to *, inclusive` (original_commit_for_fix)
  - Other versions: affected

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 8.1 High, CVSS 3.1: `CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`, from CNA (Linux) (used for this record)
- 5.5 Medium, CVSS 3.1: `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`, from ADP (CISA-ADP)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0010, the 1st percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 24 Sept 2025. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2025-39889](https://www.cve.org/CVERecord?id=CVE-2025-39889)
- [NVD: CVE-2025-39889](https://nvd.nist.gov/vuln/detail/CVE-2025-39889)

### References from the CNA

- <https://git.kernel.org/stable/c/ed503d340a501e414114ddc614a3aae4f6e9eae2>
- <https://git.kernel.org/stable/c/24b2cdfc16e9bd6ab3d03b8e01c590755bd3141f>
- <https://git.kernel.org/stable/c/c6d527bbd3d3896375079f5dbc8b7f96734a3ba5>
- <https://git.kernel.org/stable/c/9e3114958d87ea88383cbbf38c89e04b8ea1bce5>
- <https://git.kernel.org/stable/c/d49798ecd26e0ee7995a7fc1e90ca5cd9b4402d6>
- <https://git.kernel.org/stable/c/d4ca2fd218caafbf50e3343ba1260c6a23b5676a>
- <https://git.kernel.org/stable/c/522e9ed157e3c21b4dd623c79967f72c21e45b78>

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2025-39889>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2025-39889/>. Everything for agents: <https://agentprime.io/llms.txt>.