CVE Intelligence
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CVE-2026-63948 — Bluetooth: L2CAP: fix chan ref leak in l2cap_chan_timeout() on !conn

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: fix chan ref leak in l2cap_chan_timeout() on !conn __set_chan_timer() takes a l2cap_chan reference via l2cap_chan_hold() before scheduling the delayed work. The normal path in l2cap_chan_timeout() drops this reference with l2cap_chan_put() at the end, but the early return when chan->conn is NULL skips the put, leaking the reference. Add the missing l2cap_chan_put() before the early return.

Published Jul 19, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.2% (30-day exploitation probability)+2

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.21%
ahead of 11% of scored CVEs · Oct 15, 2026
Affects
Linux
Linux
CVSS base
—
Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Linux Linux version 6466ee65e5b27161c846c73ef407f49dfa1bd1d9version 6.9≥ 6.8.10 and < 6.9≥ 5.4.276 and < 5.5≥ 4.19.314 and < 4.20≥ 6.6.31 and < 6.6.143≥ 6.1.91 and < 6.1.176≥ 5.15.159 and < 5.15.210
and 11 more ≥ 5.10.217 and < 5.10.259version eb86f955488c39526534211f2610e48a5cf8ead4≥ 06acb75e7ed600d0bbf7bff5628aa8f24a97978c and < 50f1bcaaaa3a80bb1c3472044bc146e8d49d51eeversion e137e2ba96e51902dc2878131823a96bf8e638ae≥ adf0398cee86643b8eacde95f17d073d022f782c and < 9dbd84990394c51f5cee1e8871bb5ff8af5ed939≥ adf0398cee86643b8eacde95f17d073d022f782c and < 08d81fe96f80a8e20c7acb573b6a45d901fcf2cd≥ adf0398cee86643b8eacde95f17d073d022f782c and < e8a5baff5be273ca07771fd2b9bb1f2a4152917b≥ adf0398cee86643b8eacde95f17d073d022f782c and < 107c826e4ef9ec5ad8f60e6fe64d8d5325ba508f≥ 955b5b6c54d95b5e7444dfc81c95c8e013f27ac0 and < 63cd225cc13d782a85e2a73c04d0d350153eada1≥ 8960ff650aec70485b40771cd8e6e8c4cb467d33 and < 8894c2010435a56ce7c6c2a8785860c13554df2f≥ e97e16433eb4533083b096a3824b93a5ca3aee79 and < b5c59a5b469e2a809a2d57eda4ded94235971060
Vulnerable CVE Program (cve.org) e CISA ADP

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Not enough vector or weakness data: use the affected application’s logs as a starting point.
application logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Record published
    Oct 15, 2026
  • Affected products added · linux/linux
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · → Awaiting Analysis
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Jul 19, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

8 on the record

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

  • CVE-2026-99999 ipv4: validate checksum_start before completing checksum 22h
  • CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 22h
  • CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
  • CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
  • CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
  • CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No CVSS score published by NVD, the CNA, CISA or GitHub so far.
  • No fixed version, patch or mitigation documented.
  • No CISA SSVC assessment.
  • No CWE classification.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-63948 is "Bluetooth: L2CAP: fix chan ref leak in l2cap_chan_timeout() on !conn", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.21% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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