Jail escape by a privileged user via nullfs
By default, jailed processes cannot mount filesystems, including nullfs(4). However, the allow.mount.nullfs option enables mounting nullfs filesystems, subject to privilege checks. If a privileged user within a jail is able to nullfs-mount directories, a limitation of the kernel's path lookup logic allows that user to escape the jail's chroot, yielding access to the full filesystem of the host or parent jail. In a jail configured to allow nullfs(4) mounts from within the jail, the jailed root user can escape the jail's filesystem root.
Noroxi analysis
No Noroxi analysis for this record yet
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We use this product, ask for help- Published
- Mar 9, 2026
- Updated
- Jun 17, 2026
- EPSS
- 0.1% · 1th percentile
- CWE
- CWE-269
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Report tools
Action score
35
Monitor
Low priority for now.
- CVSS
- 35 / 40 · 8.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| freebsd | freebsd | cpe:2.3:o:freebsd:freebsd |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- freebsd freebsd13.5
- freebsd freebsd14.3
Versions reported by the vendor
Affected version ranges reported by the assigning authority (freebsd). Independent of NVD's CPE analysis and usually ahead of it.
FreeBSD FreeBSD
- 14.3-RELEASE and later · before p8affected · release
- 13.5-RELEASE and later · before p9affected · release
Same product
freebsd: all recordsOther highest-scoring records for the same primary product.
- CVE-2006-0900nfsd in FreeBSD 6.0 kernel allows remote attackers to cause a denial of service via a crafted NFS mount request, as demonstrated by the Prot51Plan
- CVE-2018-17157In FreeBSD before 11.2-STABLE(r340854) and 11.2-RELEASE-p5, an integer overflow error when handling opcodes can cause memory corruption by s46Plan
- CVE-2010-1938Off-by-one error in the __opiereadrec function in readrec.c in libopie in OPIE 2.4.1-test1 and earlier, as used on FreeBSD 6.4 through 8.1-P44Plan
- CVE-2006-4304Buffer overflow in the sppp driver in FreeBSD 4.11 through 6.1, NetBSD 2.0 through 4.0 beta before 20060823, and OpenBSD 3.8 and 3.9 before 44Plan
- CVE-2020-7457In FreeBSD 12.1-STABLE before r359565, 12.1-RELEASE before p7, 11.4-STABLE before r362975, 11.4-RELEASE before p1, and 11.3-RELEASE before p42Plan
- CVE-2008-2427Stack-based buffer overflow in NConvert 4.92, GFL SDK 2.82, and XnView 1.93.6 on Windows and 1.70 on Linux and FreeBSD allows user-assisted 42Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| FreeBSD FreeBSD | p8 | Vendor (CNA) |
| FreeBSD FreeBSD | p9 | Vendor (CNA) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2025-155760 days apartJail chroot escape via fd exchange with a different jail30Monitor
- CVE-2026-4525473 days apartIncorrect libcap_net limitation list manipulation26Monitor
- CVE-2026-638643 days apartMissing large page handling in pmap_pkru_update_range()24Monitor
- CVE-2026-45256109 days apartMissing permission check in thr_kill2(2)22Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-269 · Improper Privilege ManagementCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
nvd-primary
Root cause
To simplify setup, a service account is granted broad, cluster-wide permissions. The principle of least privilege is skipped during installation.
The bug in code
The whole CWE-269 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
kind: ClusterRolerules: - apiGroups: ["*"] resources: ["*"] verbs: ["*"]Fixed
kind: Rolemetadata: namespace: lodos-systemrules: - apiGroups: ["apps"] resources: ["deployments"] verbs: ["get", "list", "update"]Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Change log
- Fix✗ → ✓
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References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.