Bluetooth: RFCOMM: validate skb length in rfcomm_recv_frame
Key facts
- Attack vector
- —
- Privileges required
- —
- User interaction
- —
- Attack complexity
- —
- Impact type
- —
- Confidentiality · integrity · availability
- —
- Fix status
- Partial Red Hat: 7 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
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).
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-93783
- 2026-10-03 Alias added: GHSA-xv96-c36m-qhm7
- 2026-10-03 Fix available: Linux/Linux@30d1d9f3495463f7c026e4c553127f79b486fcd6, Linux/Linux@3829af5fab5a22405bf1e7d69068c2ec0fce46ca, Linux/[email protected] +5 · CNA
- 2026-10-03 4 new references · CNA
- 2026-11-03 Affected versions changed · Red Hat
- 2026-11-03 CVSS score added · Red Hat
References
Other 7
- https://git.kernel.org/stable/c/fb40eda15122f6b780228639c1ead6820340ff54
- https://git.kernel.org/stable/c/3829af5fab5a22405bf1e7d69068c2ec0fce46ca
- https://git.kernel.org/stable/c/b161eacd7fa4a2d765724b5504ac6cc388e48f80
- https://git.kernel.org/stable/c/30d1d9f3495463f7c026e4c553127f79b486fcd6
- https://git.kernel.org/stable/c/67dc3b40fae71b6b11c71e7ff69bac0758818c05
- https://git.kernel.org/stable/c/bbc310caa2b6bf5fe42896ba27da0fbc12e4ac51
- https://git.kernel.org/stable/c/b230e5bf501c5edaf2eb0991cb862ac142031d4b
More Linux vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-93783 · CVE Program
- CVE-2026-93783 · NVD
- FIRST EPSS
- GHSA-xv96-c36m-qhm7 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-93783 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences