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NVD / CVE Program· CNA Linux

CVE-2026-93783: Bluetooth: RFCOMM: validate skb length in rfcomm_recv_frame

Noroxi assessment

Priority: Monitor (action score 0/100)

  • 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: 0.17% (FIRST EPSS).
  • Fixed version: Linux Linux 30d1d9f3495463f7c026e4c553127f79b486fcd6, 3829af5fab5a22405bf1e7d69068c2ec0fce46ca, 67dc3b40fae71b6b11c71e7ff69bac0758818c05; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1.

Low priority for now. Upgrade to Linux Linux 30d1d9f3495463f7c026e4c553127f79b486fcd6, 3829af5fab5a22405bf1e7d69068c2ec0fce46ca, 67dc3b40fae71b6b11c71e7ff69bac0758818c05; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1 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: RFCOMM: validate skb length in rfcomm_recv_frame rfcomm_recv_frame() casts skb->data to struct rfcomm_hdr and dereferences hdr->addr and hdr->ctrl without validating skb->len first. A truncated frame with skb->len less than the minimum header size causes an out-of-bounds read of uninitialized memory. Additionally, a zero-length frame causes skb->len-- to underflow to UINT_MAX, making skb_tail_pointer() read far past the buffer. Commit 23882b828c3c ("Bluetooth: RFCOMM: validate skb length in MCC handlers") fixed the same class of missing-length-check bugs in the MCC sub-handlers, but the top-level rfcomm_recv_frame() was left unfixed. KMSAN reports: BUG: KMSAN: uninit-value in rfcomm_run ... Uninit was created at: __alloc_skb+0x474/0xb60 vhci_write+0xe9/0x870 Fix this by rejecting frames smaller than sizeof(struct rfcomm_hdr) + 1 (the minimum frame must have a 3-byte header and a 1-byte FCS).

—No exploit Fix available
Published
Sep 24, 2026
Updated
Oct 3, 2026
EPSS
0.1% · 6th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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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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Noroxi analysis

What does it mean in your environment?

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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

    • 2.6.12affected
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before fb40eda15122f6b780228639c1ead6820340ff54affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 3829af5fab5a22405bf1e7d69068c2ec0fce46caaffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before b161eacd7fa4a2d765724b5504ac6cc388e48f80affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 30d1d9f3495463f7c026e4c553127f79b486fcd6affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 67dc3b40fae71b6b11c71e7ff69bac0758818c05affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before bbc310caa2b6bf5fe42896ba27da0fbc12e4ac51affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before b230e5bf501c5edaf2eb0991cb862ac142031d4baffected · git
    • before 2.6.12not affected · semver
    • 5.10.271 and later · up to and including 5.10.*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-2026-93781Sep 24, 2026 · scsi: core: Do not block on tag allocation in scsi_eh_lock_door()
    0Monitor
  • ← EarlierCVE-2026-93782Sep 24, 2026 · vhost-scsi: flush backend after device ioctls
    31Monitor
  • Later →CVE-2026-93784Sep 24, 2026 · wifi: cfg80211: validate IEs in cfg80211_wext_siwgenie()
    0Monitor

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 Linux30d1d9f3495463f7c026e4c553127f79b486fcd6Vendor (CNA)
Linux Linux3829af5fab5a22405bf1e7d69068c2ec0fce46caVendor (CNA)
Linux Linux67dc3b40fae71b6b11c71e7ff69bac0758818c05Vendor (CNA)
Linux Linuxb161eacd7fa4a2d765724b5504ac6cc388e48f80Vendor (CNA)
Linux Linuxb230e5bf501c5edaf2eb0991cb862ac142031d4bVendor (CNA)
Linux Linuxbbc310caa2b6bf5fe42896ba27da0fbc12e4ac51Vendor (CNA)
Linux Linuxfb40eda15122f6b780228639c1ead6820340ff54Vendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.06.6.158.1-1 · 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

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

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 (6 more)

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

All records