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PatchSiren cyber security CVE debrief

CVE-2026-87939 Drupal CVE debrief

A Cross-site Scripting (XSS) vulnerability exists in the Drupal Feed Block module, affecting versions from 0.0.0 to 2.0.2 and from 3.0.0 to 3.0.2. This issue allows for Stored XSS, which can be exploited by injecting malicious input during web page generation. The vulnerability can have significant operational impacts, including potential security breaches and data compromise. Defenders should assess exposure and prioritize updates and mitigations to prevent exploitation. The CVE record and source item provide details on the vulnerability, affected versions, and references to official advisories.

Vendor
Drupal
Product
Feed Block
CVSS
Unknown
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-22
Original CVE updated
2026-10-22
Advisory published
2026-10-22
Advisory updated
2026-10-22

Who should care

Defenders responsible for Drupal installations using the Feed Block module, especially those with versions 0.0.0 to 2.0.2 and 3.0.0 to 3.0.2, should assess exposure and prioritize updates and mitigations.

Why it matters

CVE-2026-87939 is a Stored Cross-site Scripting (XSS) vulnerability in the Drupal Feed Block module, affecting multiple versions. Defenders should verify exposure, update or patch vulnerable versions, and implement input validation to prevent exploitation.

  • Requires verification of affected versions and exposure
  • Potential for Stored XSS exploitation
  • Defenders need to update or patch vulnerable Feed Block versions
  • Implementing input validation and sanitization measures is crucial

Technical summary

The Drupal Feed Block module is vulnerable to Stored Cross-site Scripting (XSS) due to improper neutralization of input during web page generation. This affects Feed Block versions from 0.0.0 to 2.0.2 and from 3.0.0 to 3.0.2. The vulnerability allows attackers to inject malicious scripts, potentially leading to security breaches and data compromise. Defenders should review and update Feed Block versions to the latest available, implement input validation and sanitization measures, and monitor for suspicious activity to prevent Stored XSS attacks.

Defensive priority

Defenders should prioritize reviewing and updating Feed Block versions to the latest available, especially for versions 0.0.0 to 2.0.2 and 3.0.0 to 3.0.2, and implement input validation and sanitization measures to prevent Stored XSS attacks.

Recommended defensive actions

  • Review and update Feed Block to the latest version
  • Implement input validation and sanitization measures
  • Monitor for suspicious activity and implement Content Security Policy (CSP)

Evidence notes

The CVE record and source item provide details on the vulnerability, affected versions, and references to official advisories. However, the CVSS score and severity are not provided.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-87939 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-87939

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

  • CVE-2026-87939 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-87939

    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.