Cisco Unified Computing System Central Software: Improper Limitation of a Pathname to a Restricted Directory
CVE-2026-76506 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in Cisco Unified Computing System Central Software from Cisco, with a CVSS 3.1 base score of 7.6 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 Cisco Unified Computing System Central Software versions: 2.0(1e); 2.0(1a); 2.0(1h), and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.36% chance of exploitation within 30 days, higher than 72% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Cisco Unified Computing System Central Software you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco Unified Computing System Central Software | 2.0(1e); 2.0(1a); 2.0(1h); 2.0(1g); 2.0(1c); 2.0(1k); 2.0(1l); 2.0(1f); and 20 more ranges | Not stated |
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
- HighAll data handled by the component can be read.
- Integrity
- LowLimited modification of data is possible.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L. Scored by CNA (cisco.com).
Official description
A vulnerability in the web-based management interface of Cisco UCS Central Software could allow an authenticated, remote attacker to achieve remote code execution or conduct information disclosure attacks on an affected device. This vulnerability is due to insufficient validation of user-supplied input in an HTTP request. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected endpoint on an affected device. A successful exploit could allow the attacker to execute arbitrary commands, write arbitrary files to the filesystem, and obtain sensitive information. To exploit this vulnerability, the attacker must have valid user credentials on the affected device. Cisco has released software updates that address this vulnerability There are no workarounds that address this vulnerability.
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: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 8.6 High severity
- 10.0 Critical severity
- 8.4 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
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