In the Linux kernel the memfd mechanism incorrectly applies SEAL_WRITE when a process sets SEAL_EXEC. Because the implied seal is added after the check that forbids writable mappings, the vulnerability allows a memfd to appear write‑sealed while still permitting writable mappings. This breaks the contract that SEAL_WRITE provides and enables an attacker to modify the contents of a supposedly write‑sealed memory file. Based on the description, it is inferred that this could enable code injection or privilege escalation.

All Linux kernel builds that have not incorporated the recent patch are potentially impacted. The vulnerability applies to the Linux kernel as a whole; no specific kernel version range is cited, so any unpatched kernel can be exploited.

The CVSS score of 8.4 indicates a high‑severity local vulnerability. The EPSS score of less than 1% suggests a low probability of immediate public exploitation, and the flaw is not listed in the CISA KEV catalog. The vulnerability arises from a misordered check where SEAL_WRITE is applied after denying writable mappings, allowing an attacker who can create a memfd and issue the SEAL_EXEC flag to keep writable mappings while the memfd claims to be write‑sealed. This permits arbitrary memory modification or execution in a local context, potentially enabling privilege escalation or other local exploits.