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PatchSiren cyber security CVE debrief

CVE-2026-52307 ClassCMS CVE debrief

An authenticated stored cross-site scripting (XSS) vulnerability exists in ClassCMS 1CMS v5.6, specifically in the Column Management component. This allows attackers to inject crafted payloads into the title field, potentially leading to arbitrary web script or HTML execution. The vulnerability has a CVSS score of 5.4 and is classified as MEDIUM severity. Defenders should assess exposure and verify the effectiveness of current security practices. The CVE record and NVD entry provide details on the vulnerability, but additional information on affected versions, exploitation, or remediation is limited.

Vendor
ClassCMS
Product
1CMS
CVSS
MEDIUM 5.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-08
Original CVE updated
2026-09-14
Advisory published
2026-09-08
Advisory updated
2026-09-14

Who should care

Defenders responsible for ClassCMS 1CMS v5.6 deployments, particularly those with user-authenticated access to the Column Management component, should assess exposure and verify the effectiveness of current security practices.

Why it matters

CVE-2026-52307 is a MEDIUM-severity authenticated stored XSS vulnerability in ClassCMS 1CMS v5.6. Defenders should prioritize verifying exposure, assessing security practices, and implementing additional measures to prevent XSS attacks.

  • Potential for attackers to execute arbitrary web scripts or HTML via injected payloads
  • Need for defenders to verify exposure and assess current security practices
  • Importance of input validation and output encoding to prevent XSS attacks
  • Limited information available on affected versions, exploitation, or remediation

Technical summary

The vulnerability exists in the Column Management component of ClassCMS 1CMS v5.6, allowing attackers to inject crafted payloads into the title field, potentially leading to arbitrary web script or HTML execution. The vulnerability has a CVSS score of 5.4 and is classified as MEDIUM severity. The Column Management component is used for managing columns in ClassCMS 1CMS v5.6. The vulnerability is caused by a lack of input validation and output encoding in the title field.

Defensive priority

Defenders should prioritize verifying exposure of the Column Management component in ClassCMS 1CMS v5.6 and assess the effectiveness of current input validation and output encoding practices.

Recommended defensive actions

  • Verify exposure of the Column Management component in ClassCMS 1CMS v5.6
  • Assess input validation and output encoding practices for the title field
  • Implement additional security measures to prevent XSS attacks

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its CVSS score of 5.4 and severity of MEDIUM. However, additional information on affected versions, exploitation, or remediation is limited.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-52307 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-52307

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-52307 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-52307

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.