DEBIAN-CVE-2026-63952

Advisory lineage Upstream: 1 Downstream: 0
Upstream
CVE-2026-63952
Published: 19 Jul 2026, 16:17
Last modified:21 Jul 2026, 09:00

Vulnerability Summary

Overall Risk (default)
medium
34/100
CVSS Score
8.4 HIGH
3.1 (osv_debian)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

19 Jul 2026, 16:17
Published
Vulnerability first disclosed
21 Jul 2026, 09:00
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: memfd: deny writeable mappings when implying SEAL_WRITE When SEAL_EXEC is added, SEAL_WRITE is implied to make W^X. But the implied seal is set after the check that makes sure the memfd can not have any writable mappings. This means one can use SEAL_EXEC to apply SEAL_WRITE while having writeable mappings. This breaks the contract that SEAL_WRITE provides and can be used by an attacker to pass a memfd that appears to be write sealed but can still be modified arbitrarily. Fix this by adding the implied seals before the call for mapping_deny_writable() is done.

CVSS Metrics

  • v3.1•HIGH•Score: 8.4CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

Affected Systems

  • debian•linux

    < 6.12.94-1 | < 7.0.12-1

References (1)