A malformed Bluetooth Classic SDP attribute can trigger a reachable assertion in Zephyr's SDP parser. In subsys/bluetooth/host/classic/sdp.c, bt_sdp_parse_attribute() accepts an input buffer once it contains the 1-byte attribute type and 2-byte attribute id, but then unconditionally pulls an additional byte for the value type without verifying that the byte is present. A truncated 3-byte attribute (for example 09 00 09) therefore reaches net_buf_simple_pull() with insufficient remaining length, triggering the __ASSERT_NO_MSG(buf->len >= len) check and a kernel panic in assert-enabled builds (denial of service). In builds where assertions are disabled, parsing may continue past the end of the available buffer, leading to an out-of-bounds read and undefined behavior.

bt_sdp_parse_attribute() in subsys/bluetooth/host/classic/sdp.c validated only that the SDP record buffer held the type-marker byte plus the 2-byte attribute ID (a check of buf->len < 3) but then read a fourth byte, the data-element descriptor (type), via net_buf_simple_pull_u8(). Because net_buf_simple_pull_u8() dereferences buf->data[0] before its only bounds guard (an __ASSERT_NO_MSG that compiles out when CONFIG_ASSERT is disabled, the production default), a record of exactly three bytes (0x09 followed by a 2-byte attribute ID) causes a one-byte read past the end of the logical buffer. The parser is reachable from inbound, remote-controlled data: a Bluetooth BR/EDR peer acting as an SDP server returns discovery-response records that are stored verbatim in the client receive buffer and parsed via the public bt_sdp_get_attr()/bt_sdp_has_attr()/bt_sdp_record_parse() helpers. The over-read is bounded to a single byte that is used only as an internal length selector and is never leaked to the attacker; subsequent length checks then reject the malformed record. Realistic impact is therefore limited to an edge-case denial of service (a fault only if the record ends exactly at a mapped-memory boundary, or a deterministic assert panic when CONFIG_ASSERT=y). Affects Zephyr v4.3.0 and v4.4.0; fixed by adding sizeof(type) to the length check.

CWE-617

https://github.com/zephyrproject-rtos/zephyr/commit/dfac5224ab65fc7b81be2926386173c169318335

[{"vendor":"zephyrproject-rtos","product":"Zephyr","defaultStatus":"unaffected","packageName":"Zephyr","repo":"https://github.com/zephyrproject-rtos/zephyr","versions":[{"version":"*","lessThanOrEqual":"4.4.0","versionType":"git","status":"affected"}]}]

[{"vendor":"zephyrproject","product":"zephyr","defaultStatus":"unaffected","collectionURL":"https://github.com/zephyrproject-rtos/zephyr","packageName":"zephyr","programFiles":["subsys/bluetooth/host/classic/sdp.c"],"versions":[{"version":"4.3.0","lessThan":"4.5.0","versionType":"semver","status":"affected"}]}]

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

OR
          *cpe:2.3:o:zephyrproject:zephyr:*:*:*:*:*:*:*:* versions up to (including) 4.4.1

Zephyr Project: https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-p93g-3r68-cj53 Types: Exploit, Patch, Vendor Advisory

{"timestamp":"2026-06-23T12:19:37.226064Z","id":"CVE-2026-10651","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}

A malformed Bluetooth Classic SDP attribute can trigger a reachable assertion in Zephyr's SDP parser. In subsys/bluetooth/host/classic/sdp.c, bt_sdp_parse_attribute() accepts an input buffer once it contains the 1-byte attribute type and 2-byte attribute id, but then unconditionally pulls an additional byte for the value type without verifying that the byte is present. A truncated 3-byte attribute (for example 09 00 09) therefore reaches net_buf_simple_pull() with insufficient remaining length, triggering the __ASSERT_NO_MSG(buf->len >= len) check and a kernel panic in assert-enabled builds (denial of service). In builds where assertions are disabled, parsing may continue past the end of the available buffer, leading to an out-of-bounds read and undefined behavior.

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

CWE-20

CWE-617

https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-p93g-3r68-cj53

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