Linux Kernel up to 6.18.15/6.19.5 z_erofs_transform_plain out-of-bounds

Summaryinfo

A vulnerability described as critical has been identified in Linux Kernel up to 6.18.15/6.19.5. Impacted is the function z_erofs_transform_plain. Such manipulation leads to out-of-bounds. This vulnerability is referenced as CVE-2026-43166. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.15/6.19.5. It has been rated as problematic. Affected by this issue is the function z_erofs_transform_plain. The manipulation with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: erofs: fix interlaced plain identification for encoded extents Only plain data whose start position and on-disk physical length are both aligned to the block size should be classified as interlaced plain extents. Otherwise, it must be treated as shifted plain extents. This issue was found by syzbot using a crafted compressed image containing plain extents with unaligned physical lengths, which can cause OOB read in z_erofs_transform_plain().

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-43166 since 05/01/2026. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 05/17/2026).

Upgrading to version 6.18.16 or 6.19.6 eliminates this vulnerability. Applying the patch 9d5a97bc71ed5783687705c708454c4453aa91d1/d3790f26d38606f020212486359b84632c19d08b/4a2d046e4b13202a6301a993961f5b30ae4d7119 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3
• 6.19.4
• 6.19.5

License

• open-source

Website

• Vendor: https://www.kernel.org/

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