CVE-2026-93783Bluetooth: RFCOMM: validate skb length in rfcomm_recv_frame
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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).
- CVSS
- Not yet scored
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Oct 3, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before fb40eda15122f6b780228639c1ead6820340ff54; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 3829af5fab5a22405bf1e7d69068c2ec0fce46ca; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before b161eacd7fa4a2d765724b5504ac6cc388e48f80; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 30d1d9f3495463f7c026e4c553127f79b486fcd6; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 67dc3b40fae71b6b11c71e7ff69bac0758818c05; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before bbc310caa2b6bf5fe42896ba27da0fbc12e4ac51; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before b230e5bf501c5edaf2eb0991cb862ac142031d4b | CNA record |
References
- 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
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.