Apache NiFi Registry: Improper Limitation of a Pathname to a Restricted Directory
CVE-2026-87976 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in Apache NiFi Registry from Apache, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected Apache NiFi Registry versions: 0.4.0 through 2.11.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.79% chance of exploitation within 30 days, higher than 57% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Nifi to 2.12.0 or a later version.
- Read the advisory on lists.apache.org for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apache | Apache NiFi Registry | 0.4.0 through 2.11.0 | Not stated |
| Apache | Nifi | 0.4.0 up to, but not including, 2.12.0 | 2.12.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.2 | High | CNA (apache.org) |
| CVSS 3.1 | 8.1 | High | NVD |
Official description
Apache NiFi Registry 0.4.0 through 2.11.0 are subject to path manipulation when storing extension bundle content using group, artifact, and version coordinates from uploaded NAR manifests. The default file persistence provider used coordinates as filesystem path components without rejected parent-directory names, and the path-containment check compared an unnormalized resolved path. An authenticated user authorized to write and delete bundles in a bucket can upload a NAR with a crafted manifest resulting in file system operations outside of the file persistence directory. Upgrading to Apache NiFi Registry 2.12.0 is the recommended mitigation, which rejects parent-directory coordinates and requires a normalized path to remain a strict child of the storage root location.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
How developers prevent this class of flaw
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.
More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- openwall.com/lists/oss-security/2026/09/16/11Mailing List, Third Party Advisory
Other vulnerabilities in Apache NiFi Registry
- 8.8 High severity
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 7.8 High severity
- 9.8 Critical severity
- 7.5 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
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