FileRun: Deserialization of Untrusted Data
CVE-2026-73699 is a high-severity deserialization of untrusted data vulnerability in FileRun, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. The record lists version 2026.3.0 as the first without the flaw, so updating FileRun to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.78% 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 FileRun to 2026.3.0 or a later version.
Affected products and versions
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
- HighAdministrator-level access is required first.
- 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
- 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:H/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.6 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 7.2 | High | CNA (vulncheck.com) |
Official description
FileRun before 2026.3.0 contains a PHP object injection vulnerability that allows authenticated attackers to execute arbitrary code by exploiting incorrect options passed to unserialize() in the Perms::getPerms() method, where a positional array is used instead of the required named-key array to disable class instantiation. Attackers with database write access can inject a serialized gadget chain into the permissions table columns processed on every authenticated page load to write arbitrary files, such as PHP webshells, to web-accessible paths.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How developers prevent this class of flaw
- If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
- Explicitly define a final object() to prevent deserialization.
More Deserialization of Untrusted Data vulnerabilities (CWE-502)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
References
Patches and release notes
Other references
Other vulnerabilities in FileRun
- 7.2 High severity
- 7.2 High severity
- 8.8 High severity
- 8.8 High severity
Recent Deserialization of Untrusted Data vulnerabilities
- 8.1 High severity
- 8.1 High severity
- 8.1 High severity
- 8.1 High severity
- 7.5 High severity
- 9.8 Critical severity
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