CVE-2026-91831

Status: DeferredLow (3.8)—

Severity3.8Low · CVSS 3.1

Exploitation probability0.16 %higher than 5% of CVEs

Active exploitationNonot in the CISA catalog

Public exploitNot knownno public code found

The Subscribe to Comments WordPress plugin before 2.3.3 does not sanitise newline characters from a notification sender-name setting before using it in e-mail headers, allowing users with Author-level access and above to inject arbitrary e-mail headers, such as a hidden Bcc, and to spoof the sender.

CVSS

Base score: 3.8
Version: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.16 %
Percentile among all scored CVEs: 5
Score date: 10/20/2026

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 movement60 %

Inferred by deterministic rules from the CVSS vector and CWE. Indicative only.

ATT&CK mitigations that cover these techniques

Vulnerability Scanning Threat Intelligence Program Privileged Account Management Network Segmentation Disable or Remove Feature or Program Application Isolation and Sandboxing

Affected technologies (1)

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

Markjaquith — Subscribe TO Comments^AI

CWEs

CWE-93

References

Show 1 references

https://wpscan.com/vulnerability/6cd60f78-f5e2-4b4a-8d50-7d2bc4f981ee/

Raw JSON (NVD)

Show

{
  "id": "CVE-2026-91831",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-91831",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-10-19T09:25:57.636205Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "contact@wpscan.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 3.8,
          "attackVector": "NETWORK",
          "baseSeverity": "LOW",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N",
          "integrityImpact": "LOW",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "HIGH",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 2.5,
        "exploitabilityScore": 1.2
      }
    ]
  },
  "affected": [
    {
      "source": "contact@wpscan.com",
      "affectedData": [
        {
          "vendor": "Unknown",
          "product": "Subscribe to Comments",
          "versions": [
            {
              "status": "affected",
              "version": "2.3",
              "lessThan": "2.3.3",
              "versionType": "semver"
            }
          ],
          "collectionURL": "https://wordpress.org/plugins",
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-10-19T07:16:32.187",
  "references": [
    {
      "url": "https://wpscan.com/vulnerability/6cd60f78-f5e2-4b4a-8d50-7d2bc4f981ee/",
      "source": "contact@wpscan.com"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "description": [
        {
          "lang": "en",
          "value": "CWE-93"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Subscribe to Comments WordPress plugin before 2.3.3 does not sanitise newline characters from a notification sender-name setting before using it in e-mail headers, allowing users with Author-level access and above to inject arbitrary e-mail headers, such as a hidden Bcc, and to spoof the sender."
    }
  ],
  "lastModified": "2026-10-19T21:02:51.987",
  "sourceIdentifier": "contact@wpscan.com"
}