Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-6443 is a critical-severity Embedded Malicious Code (CWE-506) vulnerability in Anchor (inferred from references). Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Embedded Payloads (T1027.009); ranked at the 40th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SC-44 (Detonation Chambers) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-6443, published on 2026-04-17, is a critical vulnerability (CVSS 9.8, CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) classified under CWE-506 (Embedded Malicious Code). It affects all plugins by Essentialplugin for WordPress across various versions. The vulnerability arises from the plugins being sold to a malicious threat actor, who embedded a backdoor into all acquired plugins.
The threat actor can exploit this backdoor remotely against any site running the affected plugins, requiring no authentication, privileges, or user interaction. Exploitation enables the actor to maintain persistent access to the site and inject spam, with potential for high-impact compromise of confidentiality, integrity, and availability.
Advisories linked to this CVE, including those from Wordfence and Anchor.host, provide further details on the incident; practitioners should consult these references for recommended mitigations such as plugin removal or updates where available.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-23384
Vulnerability Data
All plugins by Essentialplugin for WordPress are vulnerable to an injected backdoor in various versions. This is due to the plugin being sold to a malicious threat actor that embedded a backdoor in all of the plugin's they acquired. This…
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makes it possible for the threat actor to maintain a persistent backdoor and inject spam into the affected sites.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 3 hardening rules · 2 OS baselines
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Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover embedded malicious code before release.
Detonation chambers can reveal embedded malicious code through controlled execution analysis.
Integrity verification tools directly detect unauthorized or malicious code insertions.
Tamper-resistance and detection mechanisms identify malicious code introduced via the supply chain.
Component authenticity requirements reduce the chance malicious code is embedded by developers or suppliers.
Component authenticity controls stop introduction of malicious or counterfeit code into the product.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Assessing authenticity and integrity before acquisition catches embedded malicious code.
Secure SDLC practices directly prevent introduction of malicious code during development.
Due diligence prior to supplier relationships helps avoid sources of embedded malicious code.
Supplier risk assessment reduces likelihood of receiving products containing malicious code.
Pre-acquisition assessment of critical suppliers mitigates risk of malicious code in procured software.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Requiring suppliers to furnish component lists, attestations, and cryptographic verification of delivered artefacts makes it harder for an attacker to embed hidden malicious code that would otherwise go undetected through the supply chain.
Checks that executed code has not been tampered with and monitoring for malware-associated activity reduce the likelihood that hidden malicious code remains active.
Banning unapproved or unknown software and requiring testing plus authorization reduces the chance that hidden malicious code will be introduced into production environments.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 9 (1 rule)
- V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-506
RHEL 9 (1 rule)
- V-258078 RHEL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-506