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NVD / CVE Program· CNA Linux

CVE-2026-90255: Bluetooth: hci_conn: fix the SCO setup context lifetime

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: 0.33% (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 37cfec41365c826d5496ef5d00c9e215eee53aa2, 42de40abe25db9211107af8896d0fd741f10648d, 4d7b1c834d2775b73c65e4888e01f5af8b477fe9; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1.

Low priority for now. Upgrade to Linux Linux 37cfec41365c826d5496ef5d00c9e215eee53aa2, 42de40abe25db9211107af8896d0fd741f10648d, 4d7b1c834d2775b73c65e4888e01f5af8b477fe9; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1 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_conn: fix the SCO setup context lifetime hci_setup_sync() queues a conn_handle_t with a NULL destroy callback, so the context is only freed if hci_enhanced_setup_sync() actually runs. An entry that is cancelled instead is leaked, as _hci_cmd_sync_cancel_entry() does not release entry->data when there is no destroy callback, and hci_cmd_sync_clear() cancels every pending entry when the controller is unregistered. The context also stores a bare hci_conn pointer, so the connection can be freed while the work is queued. The dequeue in hci_conn_del() does not cover it either, as it matches on entry->data == conn and entry->data is the wrapper here. Same problem as commit 2f5d635ad590 ("Bluetooth: hci_sync: hold conn in hci_connect_acl/le_sync() callbacks"). Hold the connection and release both from a destroy callback. The submission failure path drops both, since hci_cmd_sync_submit() does not call the destroy callback when it fails to queue.

HighCVSS 8.8 · v3.1—No exploit Fix available
Published
Sep 17, 2026
Updated
Oct 19, 2026
EPSS
0.3% · 27th percentile
CWE
—

Report tools

JSON

Action score

35

Monitor

Low priority for now.

CVSS
35 / 40 · 8.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

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.

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

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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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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.

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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

    • 6.1affected
    • e07a06b4eb417f5271d33ce2240e93c62d98b7b4 and later · before 37cfec41365c826d5496ef5d00c9e215eee53aa2affected · git
    • e07a06b4eb417f5271d33ce2240e93c62d98b7b4 and later · before 9a2ba69cebe3fc5a3d4fa8eaaad3c42862723c27affected · git
    • e07a06b4eb417f5271d33ce2240e93c62d98b7b4 and later · before a661de0ee29d0915c5e924edf91d2be2b4d35baeaffected · git
    • e07a06b4eb417f5271d33ce2240e93c62d98b7b4 and later · before c1fe3c74a89a7749cba3caa0dd91236049c66116affected · git
    • e07a06b4eb417f5271d33ce2240e93c62d98b7b4 and later · before 4d7b1c834d2775b73c65e4888e01f5af8b477fe9affected · git
    • e07a06b4eb417f5271d33ce2240e93c62d98b7b4 and later · before 42de40abe25db9211107af8896d0fd741f10648daffected · git
    • before 6.1not affected · semver
    • 6.1.188 and later · up to and including 6.1.*not affected · semver
    • 6.6.157 and later · up to and including 6.6.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

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-2026-90253Sep 17, 2026 · Bluetooth: MGMT: free the mesh send cancel command when it is cancelled
    0Monitor
  • ← EarlierCVE-2026-90254Sep 17, 2026 · Bluetooth: hci_sync: free the advertising instance on the failure and cancel paths
    0Monitor
  • Later →CVE-2026-90256Sep 17, 2026 · Bluetooth: L2CAP: use proto_lock for l2cap_data to fix l2cap_disconn_ind
    35Monitor

Remediation

Which version to upgrade to

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

Product / packageFixed versionSource
Linux Linux37cfec41365c826d5496ef5d00c9e215eee53aa2Vendor (CNA)
Linux Linux42de40abe25db9211107af8896d0fd741f10648dVendor (CNA)
Linux Linux4d7b1c834d2775b73c65e4888e01f5af8b477fe9Vendor (CNA)
Linux Linux9a2ba69cebe3fc5a3d4fa8eaaad3c42862723c27Vendor (CNA)
Linux Linuxa661de0ee29d0915c5e924edf91d2be2b4d35baeVendor (CNA)
Linux Linuxc1fe3c74a89a7749cba3caa0dd91236049c66116Vendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0—Microsoft (MSRC)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.06.6.157.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package 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.

No nightly-computed relations.

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).

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)

—

CVSS vector

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

nvd-secondary

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

  1. Fix✗ → ✓

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References

Show all references (5 more)

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

All records