CVE-2026-91051

Status: DeferredMedium (6.6)—

The EWWW Image Optimizer WordPress plugin before 8.8.0 does not prevent authenticated users with author-level permissions from storing a serialized value in a post meta field that is deserialized when the post is rendered, allowing them to perform PHP Object Injection, which can lead to remote code execution when a suitable gadget chain is present via another installed EWWW Image Optimizer WordPress plugin before 8.8.0 or .

CVSS

Version: 3.1
Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Base score: 6.6

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.35%
Percentile among all scored CVEs: 26
Score date: 10/5/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1210 Exploitation of Remote Serviceslateral movement75 %
Primary impactT1059 Command and Scripting Interpreterexecution85 %
Secondary impactT1078 Valid Accountsstealth · persistence · privilege escalation · initial access60 %

RCE vía PHP Object Injection (CWE-502) requiere privilegios autenticados (PR:H) con acceso a servicio remoto WordPress. El impacto primario es ejecución de código mediante gadget chain; secundario, abuso de credenciales de autor.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Privileged Account Management Disable or Remove Feature or Program Application Developer Guidance Active Directory Configuration Vulnerability Scanning User Training

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Ewww — Image Optimizer^AI

CWEs

CWE-502

References

https://wpscan.com/vulnerability/e24a9497-8fb4-4067-8421-194725455d55/

Raw JSON (NVD)

Show

{
  "id": "CVE-2026-91051",
  "cveTags": [],
  "metrics": {
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      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-91051",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-09-30T13:23:29.745094Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 6.6,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "HIGH",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 0.7
      }
    ]
  },
  "affected": [
    {
      "source": "contact@wpscan.com",
      "affectedData": [
        {
          "vendor": "Unknown",
          "product": "EWWW Image Optimizer",
          "versions": [
            {
              "status": "affected",
              "version": "8.6.0",
              "lessThan": "8.8.0",
              "versionType": "semver"
            }
          ],
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-09-30T06:17:09.173",
  "references": [
    {
      "url": "https://wpscan.com/vulnerability/e24a9497-8fb4-4067-8421-194725455d55/",
      "source": "contact@wpscan.com"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
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      "description": [
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      "lang": "en",
      "value": "The EWWW Image Optimizer WordPress plugin before 8.8.0 does not prevent authenticated users with author-level permissions from storing a serialized value in a post meta field that is deserialized when the post is rendered, allowing them to perform PHP Object Injection, which can lead to remote code execution when a suitable gadget chain is present via another installed EWWW Image Optimizer WordPress plugin before 8.8.0 or ."
    }
  ],
  "lastModified": "2026-09-30T16:28:31.510",
  "sourceIdentifier": "contact@wpscan.com"
}