CVE-2026-63976
HIGHDescription
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: l2cap: clear chan->ident on ECRED reconfiguration success l2cap_ecred_reconf_rsp() returns early on success without clearing chan->ident. Every other L2CAP response handler (l2cap_ecred_conn_rsp, l2cap_le_connect_rsp, l2cap_config_rsp) clears chan->ident after a successful transaction to prevent the channel from matching subsequent responses with the recycled ident value. A remote attacker that completed a reconfiguration as the peer can replay a failure response with the stale ident, causing the kernel to match and destroy the already-established channel via l2cap_chan_del(chan, ECONNRESET). Clear chan->ident for all matching channels on success, and harden the failure path by using l2cap_chan_hold_unless_zero() consistent with other L2CAP handlers (l2cap_le_command_rej, __l2cap_get_chan_by_ident).
How to fix
This vulnerability affects an unusually large number of packages. The highest-confidence fixes are shown above; the full list is longer. Check the referenced advisories for complete coverage.
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploit Intelligence
Moderate risk: more likely to be exploited than 47% of all known CVEs.
References
Related Vulnerabilities
Other CWE-694 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2020-15187 | Low | 3.0 | 1.5% | - | Fix |
| CVE-2021-3436 | Medium | 4.3 | 1.0% | - | - |
| CVE-2020-15185 | Low | 2.2 | 0.9% | - | Fix |
| CVE-2023-20100 | Medium | 6.8 | 0.8% | - | - |
| CVE-2026-102634 | High | 7.5 | 0.6% | - | - |
| CVE-2026-71327 | High | 8.1 | 0.5% | - | Fix |
Common questions
How do I fix CVE-2026-63976?
Published advisories record a fix for 230 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.
Is CVE-2026-63976 being actively exploited?
Not that we know of. CVE-2026-63976 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.57% is the estimated probability that it will be exploited in the next 30 days. That is higher than 47% of all scored CVEs.
How severe is CVE-2026-63976?
CVE-2026-63976 has a CVSS v3 base score of 8.8, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-63976 affect?
Published advisories record a fix for linux (Debian), linux (Ubuntu), linux-aws (Ubuntu), linux-aws-5.15 (Ubuntu), and 226 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-63976
Markdown
[](https://tridentstack.com/cve/CVE-2026-63976)HTML
<a href="https://tridentstack.com/cve/CVE-2026-63976"><img src="https://tridentstack.com/cve/badge/CVE-2026-63976.svg" alt="CVE-2026-63976"></a>Check your Linux endpoints for this class of vulnerability
TridentStack Control continuously scans Linux endpoints for known vulnerabilities and deploys the fixes from the same console. 200 endpoints free forever, no credit card.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-10-19.