8.8

CVE-2025-68304: Bluetooth: hci_core: lookup hci_conn on RX path on protocol side

Deferred
AliasesUBUNTU-CVE-2025-68304DEBIAN-CVE-2025-68304
Published 16-12-2025Last modified 15-10-2026

Vulnerability summary

CVE-2025-68304 is a high (CVSS 8.8) vulnerability in linux. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 14.2% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 8.8, adjacent network); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
8.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.23%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 7 · Related 7
USN-8094-1USN-8094-2USN-8094-3USN-8094-4USN-8094-5USN-8152-1

Timeline

  1. 16-12-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: lookup hci_conn on RX path on protocol side The hdev lock/lookup/unlock/use pattern in the packet RX path doesn't ensure hci_conn* is not concurrently modified/deleted. This locking appears to be leftover from before conn_hash started using RCU commit bf4c63252490b ("Bluetooth: convert conn hash to RCU") and not clear if it had purpose since then. Currently, there are code paths that delete hci_conn* from elsewhere than the ordered hdev->workqueue where the RX work runs in. E.g. commit 5af1f84ed13a ("Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync") introduced some of these, and there probably were a few others before it. It's better to do the locking so that even if these run concurrently no UAF is possible. Move the lookup of hci_conn and associated socket-specific conn to protocol recv handlers, and do them within a single critical section to cover hci_conn* usage and lookup. syzkaller has reported a crash that appears to be this issue: [Task hdev->workqueue] [Task 2] hci_disconnect_all_sync l2cap_recv_acldata(hcon) hci_conn_get(hcon) hci_abort_conn_sync(hcon) hci_dev_lock hci_dev_lock hci_conn_del(hcon) v-------------------------------- hci_dev_unlock hci_conn_put(hcon) conn = hcon->l2cap_data (UAF)

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.23%

Chance of exploitation in the next 30 days

Percentile

14%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.23% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: adjacent network, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu132 products
  • linuxAll versions (No fix recorded) | < 6.17.0-19.19
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 6.17.0-1009.9
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linuxAll versions (No fix recorded) | < 6.17.11-1
Linux1 product
  • linux≥ 5af1f84ed13a416297ab9ced7537f4d5ae7f329a, < ec74cdf77310c43b01b83ee898a9bd4b4b0b8e93 | ≥ 5af1f84ed13a416297ab9ced7537f4d5ae7f329a, < 79a2d4678ba90bdba577dc3af88cc900d6dcd5ee | cd55c13bbb3d093ae601aa97e588ed4c1390ebb1 | 4d3ca4a9aaf0aa798a6be372dc0fc3a29e37dd57 | 80265dd1d944c3f33e52375b5dbe654980bd2688 | ≥ 6.1.149, < 6.2 | ≥ 6.4.16, < 6.5 | ≥ 6.5.3, < 6.6 | 6.6

3 vendors · 134 products

References

13 links
Show all 13 references