CVE-2026-19116: WP User Frontend < 4.3.11 - Subscriber+ PHP Object Injection via Frontend Post Edit Form
Noroxi assessment
Priority: Monitor (action score 35/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.74% (FIRST EPSS); higher than 55% of all records.
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: Unknown User Frontend 4.3.11.
Low priority for now. Upgrade to Unknown User Frontend 4.3.11 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
The User Frontend WordPress plugin before 4.3.11 does not prevent user-supplied field values from being deserialized when a submitted post is reopened in its frontend editing form, allowing authenticated users with subscriber-level access and above to perform PHP Object Injection, which may lead to remote code execution when a suitable gadget chain is present on the site.
- Published
- Sep 2, 2026
- Updated
- Sep 3, 2026
- EPSS
- 0.7% · 55th percentile
- CWE
- CWE-502
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 · 0.7%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
Is User Frontend – Membership, User Registration, User Profile, User Directory & Content Restriction with Frontend Post Submission on your site?
WP Lens reads your site's plugin, theme and WordPress versions from the outside and matches them to known vulnerabilities. Works without an account.
Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
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Versions reported by the vendor
Affected version ranges reported by the assigning authority (WPScan). Independent of NVD's CPE analysis and usually ahead of it.
Unknown User Frontend
- before 4.3.11affected · semver
Same product
unknown: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-75823WP User Frontend 3.5.29 - 4.3.11 - Unauthenticated Privilege Escalation via Registration Role Encryption29Monitor
- CVE-2026-14558WP User Frontend < 4.3.10 - Editor+ PHP Object Injection via AI Form Builder28Monitor
- CVE-2026-75824WP User Frontend 2.5.8 - 4.3.11 - Unauthenticated Account Creation with Registration Disabled21Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-14567Aug 28, 2026 · WP User Frontend < 4.3.10 - Unauthenticated User Email and Phone Disclosure via User Directory21Monitor
- Later →CVE-2026-17563Sep 2, 2026 · WP User Frontend < 4.3.11 - Unauthenticated Post Creation via Subscription-Gated Form21Monitor
- Later →CVE-2026-115277Oct 30, 2026 · WP User Frontend < 4.3.14 - Reflected XSS via 'field_attr' Parameter18Monitor
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 |
|---|---|---|
| Unknown User Frontend | 4.3.11 | 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.
- WPScancoordinator
- Erwan LR (WPScan)finder
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-145585 days apartWP User Frontend < 4.3.10 - Editor+ PHP Object Injection via AI Form Builder28Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
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Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet 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
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-502 · Deserialization of Untrusted DataCVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-secondary
Root cause
Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.
The bug in code
The whole CWE-502 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
payload = sock.recv(65536)
job = pickle.loads(payload)Fixed
payload = sock.recv(65536)
if not hmac.compare_digest(sign(payload), header_sig):
raise PermissionError("invalid signature")
job = JobSchema.validate(json.loads(payload))Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
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Change log
- Fix✗ → ✓
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References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.