Security readout for executives and security teams
Plain-English summary
CVE-2026-27084 is a critical vulnerability in the WordPress Buisson theme by ThemeREX, affecting versions through 1.1.11. It could let an unauthenticated attacker trigger PHP object injection through unsafe deserialization. For businesses, exposed WordPress sites using this theme should be treated as high-priority until vendor guidance is confirmed.
Executive priority
Treat this as urgent for any public WordPress site using Buisson. The vulnerability is rated critical and requires no authentication or user interaction according to CVSS. Immediate asset validation is the key business action because exposure depends on theme usage.
Technical view
The CVE describes CWE-502 deserialization of untrusted data in ThemeREX Buisson, resulting in PHP object injection. The CVSS 3.1 score is 9.8 with network attack vector, low complexity, no privileges, and no user interaction. Public sources identify Buisson through version 1.1.11 as affected.
Likely exposure
Exposure is limited to WordPress installations using the ThemeREX Buisson theme at version 1.1.11 or earlier. Sites not using this theme are not indicated as affected by the provided sources. The source bundle does not confirm whether a patched version exists.
Exploitation context
The CVE is not listed as KEV in the provided bundle, and no cited source confirms active exploitation. The CVSS vector indicates remote, unauthenticated exploitation is theoretically possible with low attack complexity, which raises urgency for internet-facing WordPress sites.
Researcher notes
Public detail is sparse. The CVE and Patchstack entry identify unsafe deserialization leading to PHP object injection, but the provided sources do not include exploit details, indicators of compromise, or confirmed remediation. Avoid assuming active exploitation without additional evidence.
Mitigation direction
- Inventory WordPress sites for the ThemeREX Buisson theme.
- Identify any Buisson installations at version 1.1.11 or earlier.
- Check Patchstack and ThemeREX guidance for patched versions or workarounds.
- Disable or replace the theme if no safe update is available.
- Prioritize internet-facing and business-critical WordPress sites first.
Validation and detection
- Confirm whether Buisson is installed on each WordPress instance.
- Record the installed Buisson theme version.
- Compare installed versions against the affected range: through 1.1.11.
- Review vendor and Patchstack advisories for remediation status.
- Monitor web and application logs for unusual WordPress activity.
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-502: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. 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-2026-27084 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
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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.
CVSS vector scores
1 official scoreWe 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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
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.
Deserialization of Untrusted Data
Deserialization of Untrusted Data represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.