CVE-2026-99052
N/AIn the Linux kernel, the following vulnerability has been resolved: selinux: preserve NATIVE_LABELS on already-initialized sb in set_mnt_opts When an NFSv4 filesystem exported with security_label is mounted a second time, sget_fc() returns the existing superblock and nfs_get_root() calls security_sb_set_mnt_opts() again on it. Since the superblock is already SB_INITIALIZED, selinux_set_mnt_opts() takes an early exit without setting SECURITY_LSM_NATIVE_LABELS in *set_kern_flags. nfs_get_root() then sees kflags without SECURITY_LSM_NATIVE_LABELS set and clears NFS_CAP_SECURITY_LABEL on the shared nfs_server, silently disabling per-file labeling for both the new and the original mount. Commit 3815a245b501 ("security/selinux: fix SECURITY_LSM_NATIVE_LABELS on reused superblock") fixed the same problem in selinux_sb_clone_mnt_opts(). The reused-superblock path for a plain second mount now goes through sb_set_mnt_opts rather than sb_clone_mnt_opts, so it needs the same treatment: on both SE_SBINITIALIZED early exits, set SECURITY_LSM_NATIVE_LABELS in *set_kern_flags when the superblock was already using SECURITY_FS_USE_NATVE.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.2%chance of exploitation in 30 days · 6th percentile
Impact if exploited
—CVSS · not scored
- No impact metrics
Proof of concept
No public PoC is currently catalogued.
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References and research data (JSON)
References
Advisories
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-108847 EUVD · EUVD-2026-108847
Technical & other
- https://git.kernel.org/stable/c/a545def625860d4ccedc14fe45e884a62a041cefCVE record · Linux · Updated 2026-10-23T12:22:34.168Z
NVD · CVE-2026-99052 · Updated 2026-10-23T13:17:28.747 - https://git.kernel.org/stable/c/a6da93c625b3557dd23ff6db45d2d1bafeae1565CVE record · Linux · Updated 2026-10-23T12:22:34.168Z
NVD · CVE-2026-99052 · Updated 2026-10-23T13:17:28.747 - https://git.kernel.org/stable/c/5509d498e1b9edafebd5a60ba3cb9ecfda23dc2bCVE record · Linux · Updated 2026-10-23T12:22:34.168Z
NVD · CVE-2026-99052 · Updated 2026-10-23T13:17:28.747 - https://git.kernel.org/stable/c/c997832414f1d846de0a1fa38d7d4f62ba2ea917CVE record · Linux · Updated 2026-10-23T12:22:34.168Z
NVD · CVE-2026-99052 · Updated 2026-10-23T13:17:28.747 - https://git.kernel.org/stable/c/28b7260548af3d35773477993ad4e4de41578dd7CVE record · Linux · Updated 2026-10-23T12:22:34.168Z
NVD · CVE-2026-99052 · Updated 2026-10-23T13:17:28.747