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PatchSiren cyber security CVE debrief

CVE-2026-81889 Studio-42 CVE debrief

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-08-31T21:17:52.460Z and has not been modified since then. The NVD entry is currently 8.6 HIGH. This server-side request forgery vulnerability in elFinder, prior to version 2.1.70, allows an attacker to use DNS rebinding to store the internal HTTP response body as an uploaded file, making it readable through elFinder when PHP cURL is unavailable. The issue is fixed in version 2.1.70. Developers and administrators using elFinder should review and apply the patch. They should also restrict URL uploads to trusted sources, monitor for suspicious activity, and implement additional security measures to prevent server-side request forgery. Evidence is based on official CVE and NVD records, as well as source references from GitHub, but details about potential exploits or affected systems are limited.

Vendor
Studio-42
Product
elFinder
CVSS
HIGH 8.6
CISA KEV
Not listed in stored evidence
Original CVE published
2026-08-31
Original CVE updated
2026-09-03
Advisory published
2026-08-31
Advisory updated
2026-09-03

Who should care

Developers and administrators using elFinder in their applications should be aware of this vulnerability and take immediate action to patch or mitigate it. They should review the official advisory, assess their exposure, and implement additional security measures to prevent server-side request forgery. Security teams should monitor for suspicious activity related to elFinder file uploads and verify the patch implementation.

Technical summary

The elFinder file manager, prior to version 2.1.70, is vulnerable to server-side request forgery. This is due to a bypass of server-side request forgery protections when PHP cURL is unavailable. An attacker can use DNS rebinding to store the internal HTTP response body as an uploaded file, making it readable through elFinder. The issue is fixed in version 2.1.70, and developers should review and apply the patch.

Defensive priority

High-priority defensive actions are required to address this vulnerability, as it allows for server-side request forgery and has a CVSS score of 8.6.

Recommended defensive actions

  • Review and apply the patch in elFinder version 2.1.70
  • Restrict URL uploads to trusted sources
  • Monitor for suspicious activity
  • Implement additional security measures to prevent server-side request forgery
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

Evidence is based on official CVE and NVD records, as well as source references from GitHub. However, details about potential exploits or affected systems are limited. The vulnerability allows for server-side request forgery, enabling an attacker to store the internal HTTP response body as an uploaded file, making it readable through elFinder. To verify, defenders should review the official advisory, assess their exposure, and monitor for suspicious activity related to elFinder file uploads.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-81889 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-81889

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

  • CVE-2026-81889 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-81889

    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.