NVD / CVE Program· CNA Linux

CVE-2026-68393: Bluetooth: hci_sync: extend conn_hash lookup critical sections

Noroxi assessment

Priority: Monitor (action score 35/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.24% (FIRST EPSS).
Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 38326774df6198df0cc2744cc73bf77cb741c538, 3f98e7f38e1bb761a9964a8851f9c08e9c23b3dd, 6.12.114.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 38326774df6198df0cc2744cc73bf77cb741c538, 3f98e7f38e1bb761a9964a8851f9c08e9c23b3dd, 6.12.114 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: extend conn_hash lookup critical sections Using RCU-protected pointers outside the critical sections without refcount is incorrect and may result to UAF. Extend critical section to cover both hci_conn_hash lookup and use of the returned conn. Add surrounding rcu_read_lock() also when return value is not used, in preparation for RCU lockdep requirement to hci_lookup_le_connect(). This avoids concurrent deletion of the conn before we are done dereferencing it. Also, make sure to hold hdev->lock when accessing hdev->accept_list.

HighCVSS 8.8 · v3.1—No exploit Fix available

Published: Aug 10, 2026
Updated: Oct 21, 2026
EPSS: 0.2% · 15th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 35 / 40 · 8.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Linux: 8.8; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- 94bf6380e936339a700c0b3171a49baf512aa70b, 6.15affected
- eb8b860e87b296bd1874c79a668081efd00f9754 and later · before 3f98e7f38e1bb761a9964a8851f9c08e9c23b3ddaffected · git
- 6d0417e4e1cf66fd917f06f0454958362714ef7d and later · before 83b7e67698d0b93f685875ce82c8d335436834f7affected · git
- 6d0417e4e1cf66fd917f06f0454958362714ef7d and later · before 38326774df6198df0cc2744cc73bf77cb741c538affected · git
- 6d0417e4e1cf66fd917f06f0454958362714ef7d and later · before d5efd6e4b8b0634af6843178fe1a7dd2b2178a3daffected · git
- 6.12.28 and later · before 6.12.114affected · semver
- 6.14.6 and later · before 6.15affected · semver
- before 6.15not affected · semver
- 6.12.114 and later · up to and including 6.12.*not affected · semver
- 6.18.42 and later · up to and including 6.18.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:13	linux	before 6.12.115-2	6.12.115-2
Debian:14	linux	before 7.1.6-1	7.1.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
40Plan
CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
40Plan
CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
40Plan

Published before and after this one in the same product

← EarlierCVE-2026-68388Aug 10, 2026 · smb/client: handle overlapping allocated ranges in fallocate
39Monitor
← EarlierCVE-2026-68391Aug 10, 2026 · Bluetooth: mgmt: hold reference for hci_conn in mgmt_pending_cmds
31Monitor
Later →CVE-2026-68394Aug 10, 2026 · Bluetooth: MGMT: revalidate LOAD_CONN_PARAM queued update
31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	38326774df6198df0cc2744cc73bf77cb741c538	Vendor (CNA)
Linux Linux	3f98e7f38e1bb761a9964a8851f9c08e9c23b3dd	Vendor (CNA)
Linux Linux	6.12.114	Vendor (CNA)
Linux Linux	6.15	Vendor (CNA)
Linux Linux	83b7e67698d0b93f685875ce82c8d335436834f7	Vendor (CNA)
Linux Linux	d5efd6e4b8b0634af6843178fe1a7dd2b2178a3d	Vendor (CNA)
debian:linux	6.12.115-2 · Debian:13	Package registry (OSV)
debian:linux	7.1.6-1 · Debian:14	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-681170 days aparttipc: clear sock->sk on the failed-insert path in tipc_sk_create()
39Monitor
CVE-2026-681270 days apartila: reload IPv6 header after pskb_may_pull in checksum adjust
39Monitor
CVE-2026-681440 days apartphonet: pep: fix use-after-free in pep_get_sb()
39Monitor
CVE-2026-681560 days apartlibceph: refresh auth->authorizer_buf{,_len} after authorizer update
39Monitor
CVE-2026-683810 days apartksmbd: pin conn during async oplock break notification
39Monitor
CVE-2026-684260 days apartxfrm: fix stale skb->prev after async crypto steals a GSO segment
39Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-26-0800 · Aug 11, 2026(Linux Kernel Güvenlik Bildirimi)

All national notices →

Technical details

Attack conditions

Someone on the same network segment can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Adjacent
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

SSVC exploitation— → noneOct 16, 2026, 5:07 PM UTC
Fix✗ → ✓Sep 28, 2026, 10:08 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/38326774df6198df0cc2744cc73bf77cb741c538

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records