Linux Kernel up to 7.2.6/7.3-rc2 erofs encoding error

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.2.6/7.3-rc2. It has been rated as very critical. Affected by this vulnerability is an unknown functionality of the component erofs. This manipulation causes encoding error. The identification of this vulnerability is CVE-2026-98005. The attack can only be executed locally. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 7.2.6/7.3-rc2 and classified as very critical. Affected by this vulnerability is an unknown function of the component erofs. The manipulation with an unknown input leads to a encoding error vulnerability. The CWE definition for the vulnerability is CWE-172. The product does not properly encode or decode the data, resulting in unexpected values. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: erofs: delimit inode_share cache key components Previously, inode_share keys were encoded as follows: fingerprint || domain_id It would be better to have a separator between the fingerprint and domain ID so that the fingerprint won't be parsed as part of a domain ID. Change the key encoding as follows: domain_id || '\0' || fingerprint Since domain_id is a NUL-terminated string, this makes the in-memory key indices unambiguous.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-98005 since 09/25/2026. The exploitation appears to be easy. Attacking locally is a requirement. Additional levels of successful authentication are needed for exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/25/2026).

Upgrading to version 7.2.7 or 7.3-rc3 eliminates this vulnerability. Applying the patch 16322a67336cfeea0af4b05206ef8d0e0eda55bb/96bf9831fbf423b8104f7948cd8fe7007ecfb46c is able to eliminate this problem. 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

• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.3-rc1
• 7.3-rc2

License

• open-source

Website

• Vendor: https://www.kernel.org/

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