CVE-2026-55840

Status: DeferredMedium (5.4)—

Severity5.4Medium · CVSS 3.1

Exploitation probability0.26 %higher than 17% of CVEs

Active exploitationNonot in the CISA catalog

Public exploitNot knownno public code found

Scoold is a Q&A and a knowledge sharing platform for teams. Prior to 1.69.1, the getBackToUrl() method in src/main/java/com/erudika/scoold/utils/HttpUtils.java validates the backto and returnto parameters with Strings.CI.startsWith against the configured server URL. An attacker can supply an absolute URL whose hostname begins with the legitimate hostname, causing URI.resolve() to retain the attacker URL and the prefix check to accept it. A victim who follows the crafted sign-in link can be redirected to an attacker-controlled domain after authentication, enabling phishing and possible credential or token theft. This issue is fixed in version 1.69.1.

CVSS

Base score: 5.4
Version: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.26 %
Percentile among all scored CVEs: 17
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.

ExploitationT1203 Exploitation for Client Executionexecution85 %
Primary impactT1566.002 Spearphishing Linkinitial access60 %

CWE-601: el enlace de inicio de sesión manipulado (UI:R) redirige tras autenticarse a un dominio atacante, lo que permite phishing y posible robo de credenciales o tokens.

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

User Training User Account Management Restrict Web-Based Content Audit Application Isolation and Sandboxing Exploit Protection

Affected technologies (1)

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

Erudika — Scoold^AI

CWEs

CWE-601

References

Show 4 references

Raw JSON (NVD)

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{
  "id": "CVE-2026-55840",
  "cveTags": [],
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          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-10-15T20:15:05.964680Z"
        }
      }
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    "cvssMetricV31": [
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          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
          "integrityImpact": "LOW",
          "userInteraction": "REQUIRED",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "LOW"
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        "impactScore": 2.5,
        "exploitabilityScore": 2.8
      }
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      "affectedData": [
        {
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          "versions": [
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  "published": "2026-10-15T19:17:40.823",
  "references": [
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      "url": "https://github.com/Erudika/scoold/commit/9d61f6fe15d4f9f6262812ba7fea43be8d5bb745",
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  "descriptions": [
    {
      "lang": "en",
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    }
  ],
  "lastModified": "2026-10-15T21:17:13.573",
  "sourceIdentifier": "security-advisories@github.com"
}