CVE-2026-63948: Bluetooth: L2CAP: fix chan ref leak in l2cap_chan_timeout() on !conn
Vulnerability summary
CVE-2026-63948 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 5.1% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 33 · Related 33Timeline
- 19-07-2026PublishedVulnerability first disclosed.
Description
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.
CVSS metrics
2 scores · 2 sources · 1 version- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.16%
Chance of exploitation in the next 30 days
Percentile
5%
Versus all other CVEs
30-day change
Decrease -0.06 pp
From 0.22% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu163 products
- linuxAll versions (No fix recorded) | < 5.15.0-198.208 | < 6.8.0-146.146 | < 7.0.0-28.28
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1117.124 | < 6.8.0-1066.69 | < 7.0.0-1009.9
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 06acb75e7ed600d0bbf7bff5628aa8f24a97978c, < 50f1bcaaaa3a80bb1c3472044bc146e8d49d51ee | ≥ e97e16433eb4533083b096a3824b93a5ca3aee79, < b5c59a5b469e2a809a2d57eda4ded94235971060 | ≥ 8960ff650aec70485b40771cd8e6e8c4cb467d33, < 8894c2010435a56ce7c6c2a8785860c13554df2f | ≥ 955b5b6c54d95b5e7444dfc81c95c8e013f27ac0, < 63cd225cc13d782a85e2a73c04d0d350153eada1 | ≥ adf0398cee86643b8eacde95f17d073d022f782c, < 107c826e4ef9ec5ad8f60e6fe64d8d5325ba508f | ≥ adf0398cee86643b8eacde95f17d073d022f782c, < e8a5baff5be273ca07771fd2b9bb1f2a4152917b | ≥ adf0398cee86643b8eacde95f17d073d022f782c, < 08d81fe96f80a8e20c7acb573b6a45d901fcf2cd | ≥ adf0398cee86643b8eacde95f17d073d022f782c, < 9dbd84990394c51f5cee1e8871bb5ff8af5ed939 | e137e2ba96e51902dc2878131823a96bf8e638ae | 6466ee65e5b27161c846c73ef407f49dfa1bd1d9 | eb86f955488c39526534211f2610e48a5cf8ead4 | ≥ 5.10.217, < 5.10.259 | ≥ 5.15.159, < 5.15.210 | ≥ 6.1.91, < 6.1.176 | ≥ 6.6.31, < 6.6.143 | ≥ 4.19.314, < 4.20 | ≥ 5.4.276, < 5.5 | ≥ 6.8.10, < 6.9 | 6.9
- linux_kernelEOL≥ 4.19.314, < 4.20 | ≥ 5.4.276, < 5.5 | ≥ 5.10.217, < 5.10.259 | ≥ 5.15.159, < 5.15.210 | ≥ 6.1.91, < 6.1.176 | ≥ 6.6.31, < 6.6.143 | ≥ 6.8.10, < 6.9 | ≥ 6.9.1, < 6.12.93 | ≥ 6.13, < 6.18.35 | ≥ 6.19, < 7.0.12 | 6.9 | 7.1:rc1 | 7.1:rc2 | 7.1:rc3 | 7.1:rc4 | 7.1:rc5
Debian1 product
- linux< 6.1.176-1 | < 6.12.94-1 | < 7.0.12-1
3 vendors · 166 products
