VulnerabilityPublished 23 Oct 2026

CVE-2026-99052: Linux kernel · selinux: preserve NATIVE_LABELS on already-initialized sb in set_mnt_opts

Source GCVE Database

Authoritative record:CVE-2026-99052· High

Not known to be exploited · fixed in c997832414f1d846de0a1fa38d7d4f62ba2ea917 : patch Linux kernel soon.

Data as of 26 Oct 2026, 16:00 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in c997832414f1d846de0a1fa38d7d4f62ba2ea917, a545def625860d4ccedc14fe45e884a62a041cef, a6da93c625b3557dd23ff6db45d2d1bafeae1565 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-8mqq-3q6f-v2w5

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ eb9ae686507bc5a5ca78e6b3fbe629cd5cc67864, < c997832414f1d846de0a1fa38d7d4f62ba2ea917	Fixed in c997832414f1d846de0a1fa38d7d4f62ba2ea917
LinuxLinux	Affected ≥ eb9ae686507bc5a5ca78e6b3fbe629cd5cc67864, < a545def625860d4ccedc14fe45e884a62a041cef	Fixed in a545def625860d4ccedc14fe45e884a62a041cef
LinuxLinux	Affected ≥ eb9ae686507bc5a5ca78e6b3fbe629cd5cc67864, < a6da93c625b3557dd23ff6db45d2d1bafeae1565	Fixed in a6da93c625b3557dd23ff6db45d2d1bafeae1565
LinuxLinux	Affected ≥ eb9ae686507bc5a5ca78e6b3fbe629cd5cc67864, < 5509d498e1b9edafebd5a60ba3cb9ecfda23dc2b	Fixed in 5509d498e1b9edafebd5a60ba3cb9ecfda23dc2b
LinuxLinux	Affected ≥ eb9ae686507bc5a5ca78e6b3fbe629cd5cc67864, < 28b7260548af3d35773477993ad4e4de41578dd7	Fixed in 28b7260548af3d35773477993ad4e4de41578dd7
LinuxLinux	Affected =3.11	Fixed in–

Description

In 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.

References

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