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PatchSiren cyber security CVE debrief

CVE-2026-34365 InvoiceShelf CVE debrief

A Server-Side Request Forgery (SSRF) vulnerability exists in InvoiceShelf, an open-source web & mobile app, prior to version 2.2.0. The vulnerability is located in the Estimate PDF generation module. User-supplied HTML in the estimate Notes field is passed unsanitized to the Dompdf rendering library, which can fetch remote resources referenced in the markup. This issue can be exploited directly via the PDF preview and customer view endpoints, regardless of automated email attachments being enabled. The vulnerability has been patched in version 2.2.0. Users should review their current version and upgrade if necessary.

Vendor
InvoiceShelf
Product
Unknown
CVSS
HIGH 7.6
CISA KEV
Not listed in stored evidence
Original CVE published
2026-03-31
Original CVE updated
2026-07-24
Advisory published
2026-03-31
Advisory updated
2026-07-24

Who should care

Users of InvoiceShelf, especially those who have not upgraded to version 2.2.0, should be aware of this vulnerability. This issue is particularly concerning for users who allow user-supplied input in the estimate Notes field, as it can lead to SSRF attacks. Operators, administrators, and security teams responsible for InvoiceShelf deployments should prioritize mitigation.

Technical summary

The SSRF vulnerability in InvoiceShelf arises from unsanitized user-supplied HTML in the estimate Notes field being passed to the Dompdf rendering library. This allows an attacker to inject malicious markup that can fetch remote resources, potentially leading to SSRF attacks. The vulnerability can be exploited through the PDF preview and customer view endpoints. InvoiceShelf versions prior to 2.2.0 are affected.

Defensive priority

High

Recommended defensive actions

  • Upgrade to InvoiceShelf version 2.2.0 or later
  • Validate and sanitize user-supplied input in the estimate Notes field
  • Monitor for suspicious activity related to PDF generation and customer views
  • Implement additional security measures to prevent SSRF attacks
  • 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

The CVE record was published on 2026-03-31T20:16:29.307Z and last modified on 2026-07-24T20:10:00.147Z. The NVD entry is currently Analyzed. Evidence is limited to CVE and NVD information. Defenders should verify InvoiceShelf version and PDF generation usage.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-34365 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-34365

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

  • CVE-2026-34365 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-34365

    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.