wpForo Forum: Deserialization of Untrusted Data
CVE-2026-80513 is a high-severity deserialization of untrusted data vulnerability in wpForo Forum, with a CVSS 3.1 base score of 7.5 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. The record lists version 3.1.6 as the first without the flaw, so updating wpForo Forum to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.32% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update wpForo Forum to 3.1.6 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| wpForo Forum | wpForo Forum | before 3.1.6 | 3.1.6 |
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
- HighSuccess depends on conditions outside the attacker's control.
- 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
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).
Official description
The wpForo Forum WordPress plugin before 3.1.6 does not restrict which classes may be instantiated when it deserializes a user-supplied profile field value, allowing authenticated users with Subscriber-level access and above to inject a PHP Object. No POP chain is present in the wpForo Forum WordPress plugin before 3.1.6 itself; if one is present via another installed wpForo Forum WordPress plugin before 3.1.6 or , this could lead to remote code execution, arbitrary file operations, or SQL injection. This is an incomplete fix of CVE-2026-49769.
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: none, automatable: no, technical impact: total).
References
Other references
Recent Deserialization of Untrusted Data vulnerabilities
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