CVE-2026-98457

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: validate frame length before control and FCS access l2cap_data_rcv() unpacks either a two-byte or four-byte control field without first ensuring that it is present. A short ERTM or streaming-mode frame can therefore cause an out-of-bounds read. There is a second short-frame case when CRC16 is enabled. After the control field is pulled, l2cap_check_fcs() subtracts two from skb->len without checking it. If fewer than two bytes remain, the subtraction wraps; skb_trim() leaves the buffer unchanged and the subsequent FCS load reads past the logical end of the frame. Validate that the frame contains both its control field and, when enabled, its FCS before either field is accessed.

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EPSS — Exploit Prediction

0.0018

Probability of exploitation

0.08%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/1fdbb2a712a9a162ee817c959740face80b3d929 https://git.kernel.org/stable/c/3acf6a0038ec0d4e8f4dcbfc2a557dff5f61cb70 https://git.kernel.org/stable/c/4373ba79a267947e771c438507f7b103e30bdb21 https://git.kernel.org/stable/c/6c78a213d9070b610c7f418af2c25b66180b7e37 https://git.kernel.org/stable/c/8c7556c7cd17e073bbefdc4a9a4694a207544c37 https://git.kernel.org/stable/c/965bd88ed4b4763cb765dd65885adcfa588c6b14 https://git.kernel.org/stable/c/c6a288e6001bcce16553c3853e0f5a45eaaf85c7 https://git.kernel.org/stable/c/f557274af7b94b6134692e6f26b880f1e34c15bf

Frequently Asked Questions

What is CVE-2026-98457? +

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: validate frame length before control and FCS access l2cap_data_rcv() unpacks either a two-byte or four-byte control field without first ensuring that it is present. A short ERTM or streaming-mode frame can therefore cause an out-of-bounds read. There is a second short-frame case when CRC16 is enabled. After the control field is pulled, l2cap_check_fcs() subtracts two from skb->len without checking it. If fewer than two bytes remain, the subtraction wraps; skb_trim() leaves the buffer unchanged and the subsequent FCS load reads past the logical end of the frame. Validate that the frame contains both its control field and, when enabled, its FCS before either field is accessed.

How do I check if I'm vulnerable to CVE-2026-98457? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.