CVE-2026-46155

Description

In the Linux kernel, the following vulnerability has been resolved: smb/client: fix out-of-bounds read in smb2_compound_op() If a server sends a truncated response but a large OutputBufferLength, and terminates the EA list early, check_wsl_eas() returns success without validating that the entire OutputBufferLength fits within iov_len. Then smb2_compound_op() does: memcpy(idata->wsl.eas, data[0], size[0]); Where size[0] is OutputBufferLength. If iov_len is smaller than size[0], memcpy can read beyond the end of the rsp_iov allocation and leak adjacent kernel heap memory.

CVSS v3.1 Score

9.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

EPSS — Exploit Prediction

0.0048

Probability of exploitation

0.38%

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/512d33bc8ea4ea5c19728ee118715f4b1f4d1926 https://git.kernel.org/stable/c/8d09328dfda089675e4c049f3f256064a1d1996b https://git.kernel.org/stable/c/9b3af35645ff9cd334edc130249f9a2fb2bea25f https://git.kernel.org/stable/c/a16f70a71be4b5a4eccf39a9bf09b47285f4cb7c https://git.kernel.org/stable/c/dffb44b2e06a2908e249f0f93156fc987eee1d1c

Frequently Asked Questions

What is CVE-2026-46155? +

In the Linux kernel, the following vulnerability has been resolved: smb/client: fix out-of-bounds read in smb2_compound_op() If a server sends a truncated response but a large OutputBufferLength, and terminates the EA list early, check_wsl_eas() returns success without validating that the entire OutputBufferLength fits within iov_len. Then smb2_compound_op() does: memcpy(idata->wsl.eas, data[0], size[0]); Where size[0] is OutputBufferLength. If iov_len is smaller than size[0], memcpy can read beyond the end of the rsp_iov allocation and leak adjacent kernel heap memory. It has a CVSS v3.1 base score of 9.1 (CRITICAL).

How severe is CVE-2026-46155? +

CVE-2026-46155 has a CVSS v3.1 score of 9.1 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0048, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-46155? +

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.