CVE-2026-99052 — selinux: preserve NATIVE_LABELS on already-initialized sb in set_mnt_opts
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ eb9ae686507bc5a5ca78e6b3fbe629cd5cc67864 and < a545def625860d4ccedc14fe45e884a62a041cef≥ eb9ae686507bc5a5ca78e6b3fbe629cd5cc67864 and < a6da93c625b3557dd23ff6db45d2d1bafeae1565≥ eb9ae686507bc5a5ca78e6b3fbe629cd5cc67864 and < 5509d498e1b9edafebd5a60ba3cb9ecfda23dc2b≥ eb9ae686507bc5a5ca78e6b3fbe629cd5cc67864 and < c997832414f1d846de0a1fa38d7d4f62ba2ea917≥ eb9ae686507bc5a5ca78e6b3fbe629cd5cc67864 and < 28b7260548af3d35773477993ad4e4de41578dd7version 3.11≥ eb9ae686507bc5a5ca78e6b3fbe629cd5cc67864 and < 22987d24a159ed7df3cdc9090ca5d61e58df0cac≥ eb9ae686507bc5a5ca78e6b3fbe629cd5cc67864 and < 2f0f1f5a3b89c1ed67e39be49d29ee7f5c96e039 and 1 more≥ eb9ae686507bc5a5ca78e6b3fbe629cd5cc67864 and < dc579e43b13cb65e55eabaae4f1a950e43567fb1 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 24, 2026 → Oct 30, 2026 · 7 reading(s) · max 0.21%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 3× References added · Oct 23, 2026 – Oct 30, 2026
- 1× Official description updated · Oct 23, 2026 – Oct 23, 2026
References
10 on the record
- git.kernel.org/stable/c/5509d498e1b9edafebd5a60ba3cb9ecfda23dc2b
- github.com/advisories/GHSA-8mqq-3q6f-v2w5
- git.kernel.org/stable/c/28b7260548af3d35773477993ad4e4de41578dd7
- git.kernel.org/stable/c/c997832414f1d846de0a1fa38d7d4f62ba2ea917
- git.kernel.org/stable/c/22987d24a159ed7df3cdc9090ca5d61e58df0cac
- nvd.nist.gov/vuln/detail/CVE-2026-99052
- git.kernel.org/stable/c/dc579e43b13cb65e55eabaae4f1a950e43567fb1
- git.kernel.org/stable/c/a545def625860d4ccedc14fe45e884a62a041cef
- git.kernel.org/stable/c/2f0f1f5a3b89c1ed67e39be49d29ee7f5c96e039
- git.kernel.org/stable/c/a6da93c625b3557dd23ff6db45d2d1bafeae1565
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 2d
- Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 2d
- Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 2d
- Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 2d
- Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 2d
- Unknown CVE-2026-99210 accel/rocket: clear rdev on device init failure 2d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-99052 is "selinux: preserve NATIVE_LABELS on already-initialized sb in set_mnt_opts", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.17% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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