Answer in brief
CVE-2024-26903 records a Medium severity (CVSS 5.5) vulnerability in Bluetooth: rfcomm: Fix null-ptr-deref in rfcomm_check_security. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <369f419c097e82407dd429a202cde9a73d3ae29b || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5f369efd9d963c1f711a06c9b8baf9f5ce616d85 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <81d7d920a22fd58ef9aedb1bd0a68ee32bd23e96 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8d1753973f598531baaa2c1033cf7f7b5bb004b0 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <567c0411dc3b424fc7bd1e6109726d7ba32d4f73 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3ead59bafad05f2967ae2438c0528d53244cfde5 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5f9fe302dd3a9bbc50f4888464c1773f45166bfd || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2535b848fa0f42ddff3e5255cf5e742c9b77bb26 | 369f419c097e82407dd429a202cde9a73d3ae29b, 5f369efd9d963c1f711a06c9b8baf9f5ce616d85, 81d7d920a22fd58ef9aedb1bd0a68ee32bd23e96, 8d1753973f598531baaa2c1033cf7f7b5bb004b0, 567c0411dc3b424fc7bd1e6109726d7ba32d4f73, 3ead59bafad05f2967ae2438c0528d53244cfde5, 5f9fe302dd3a9bbc50f4888464c1773f45166bfd, 2535b848fa0f42ddff3e5255cf5e742c9b77bb26 |
| Linux/Linuxgeneric | 2.6.12 | Not reported |
| Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystemgeneric | >=0 <V1.1.1 | V1.1.1 |
Published upstream
Apr 17, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 15, 2026
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: rfcomm: Fix null-ptr-deref in rfcomm_check_security During our fuzz testing of the connection and disconnection process at the RFCOMM layer, we discovered this bug. By comparing the packets from a normal connection and disconnection process with the testcase that triggered a KASAN report. We analyzed the cause of this bug as follows: 1. In the packets captured during a normal connection, the host sends a `Read Encryption Key Size` type of `HCI_CMD` packet (Command Opcode: 0x1408) to the controller to inquire the length of encryption key.After receiving this packet, the controller immediately replies with a Command Completepacket (Event Code: 0x0e) to return the Encryption Key Size. 2. In our fuzz test case, the timing of the controller's response to this packet was delayed to an unexpected point: after the RFCOMM and L2CAP layers had disconnected but before the HCI layer had disconnected. 3. After receiving the Encryption Key Size Response at the time described in point 2, the host still called the rfcomm_check_security function. However, by this time `struct l2cap_conn *conn = l2cap_pi(sk)->chan->conn;` had already been released, and when the function executed `return hci_conn_security(conn->hcon, d->sec_level, auth_type, d->out);`, specifically when accessing `conn->hcon`, a null-ptr-deref error occurred. To fix this bug, check if `sk->sk_state` is BT_CLOSED before calling rfcomm_recv_frame in rfcomm_process_rx.
Quoted source text, attributed separately from HOL analysis.