Security readout for executives and security teams
Plain-English summary
This flaw lets a low-privileged logged-in forum user close or reopen topics they should not control. It does not expose data or take over the site, but it can disrupt public discussions and moderation workflows on affected WordPress forums.
Executive priority
Treat this as a moderate-priority forum integrity issue. Prioritize public or customer-facing forums where topic closure can affect support, reputation, or community trust, but it is not indicated as a site takeover or data breach vulnerability.
Technical view
CVE-2026-28555 is a CWE-862 missing authorization issue in wpForo Forum's wpforo_close_ajax handler. An authenticated subscriber can change topic closed/open state without moderator permission. CVSS 4.0 is 5.3, with low attack complexity, low privileges required, and limited integrity impact.
Likely exposure
Exposure is limited to WordPress sites using wpForo Forum vulnerable 2.4.x builds, especially 2.4.14 as described. The source metadata also references 2.4 and 2.4.16, so confirm exact affected and fixed versions against the vendor plugin changelog.
Exploitation context
The provided sources do not show CISA KEV listing or active exploitation. Abuse requires an authenticated subscriber account and access to the forum AJAX path. Impact is operational disruption rather than confidentiality loss or full site compromise.
Researcher notes
Evidence supports a missing authorization flaw in the topic close AJAX handler. Patch details are not fully described in the bundle, so avoid assuming a specific fixed version beyond vendor guidance. No exploit-in-the-wild evidence is provided.
Mitigation direction
- Check the installed wpForo Forum version on all WordPress sites.
- Review the vendor plugin page and changelog for the fixed release guidance.
- Upgrade wpForo Forum according to official vendor guidance.
- Limit untrusted subscriber registration where forum moderation integrity matters.
- Monitor topic close and reopen events for suspicious low-privilege activity.
Validation and detection
- Inventory WordPress sites using wpForo Forum.
- Compare installed plugin versions with the CVE and vendor changelog.
- Confirm subscribers cannot close or reopen topics through normal forum workflows.
- Review logs for topic state changes by non-moderator accounts.
- Verify moderators retain expected topic management functionality after updating.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-862: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-28555 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N——VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N2.81.4VulnCheckVulnerability scoring details
Base CVSS 4.0 score
5.3MediumVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Base CVSS 3.1 score
4.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- wpForo Forum WordPress PluginCVE reference, VulnCheck · product, patch
- VulnCheck Advisory: wpForo Forum 2.4.14 Missing Authorization via Topic Close AJAX HandlerCVE reference, VulnCheck · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Missing Authorization
Missing Authorization represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.