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PatchSiren cyber security CVE debrief

CVE-2026-110765 flexprice CVE debrief

CVE-2026-110765 FlexPrice through 2.1.38 QuickBooks Webhook Signature Verification Bypass allows unauthenticated attackers to replay forged payment notifications by omitting the intuit-signature header, potentially leading to incorrect marking of invoices as paid or overpaid and manipulation of payment amounts. Defenders responsible for FlexPrice configurations and payment notification systems should assess exposure and prioritize verification of payment notification authenticity. This vulnerability has a high CVSS score of 8.2, indicating a high severity level.

Vendor
flexprice
Product
Unknown
CVSS
HIGH 8.2
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-14
Original CVE updated
2026-10-14
Advisory published
2026-10-14
Advisory updated
2026-10-14

Who should care

Defenders responsible for FlexPrice configurations and payment notification systems should assess exposure and prioritize verification of payment notification authenticity. This includes reviewing the integrity of FlexPrice configurations, restricting access to sensitive areas of the system, and monitoring for suspicious activity. Additionally, defenders should consider the potential operational impacts of this vulnerability, including the replay of forged

Why it matters

CVE-2026-110765 is a high-severity vulnerability in FlexPrice through 2.1.38 that allows unauthenticated attackers to bypass signature verification for QuickBooks webhooks. Defenders should prioritize verifying payment notification authenticity and ensuring system integrity.

  • Replay of forged payment notifications may lead to incorrect marking of invoices as paid or overpaid.
  • Unauthenticated attackers may manipulate payment amounts.

Technical summary

FlexPrice through 2.1.38 contains an authentication bypass vulnerability in HandleQuickBooksWebhook that skips signature verification when the intuit-signature header is omitted. This allows unauthenticated attackers to replay forged payment notifications, potentially leading to incorrect marking of invoices as paid or overpaid and manipulation of payment amounts. The vulnerability has a high CVSS score of 8.2, indicating a high severity level. Defenders should prioritize verifying the authenticity of payment notifications and ensuring the integrity of FlexPrice configurations.

Defensive priority

Defenders should prioritize verifying the authenticity of payment notifications and ensuring the integrity of FlexPrice configurations.

Recommended defensive actions

  • Verify the authenticity of payment notifications
  • Ensure the integrity of FlexPrice configurations
  • Restrict access to sensitive areas of the system
  • Monitor for suspicious activity
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the authentication bypass vulnerability in FlexPrice through 2.1.38. The vulnerability allows unauthenticated attackers to replay forged payment notifications by omitting the intuit-signature header.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-110765 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-110765

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

  • CVE-2026-110765 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-110765

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

Supplemental references

  • FlexPrice through 2.1.38 QuickBooks Webhook Signature Verification Bypass

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/110xxx/CVE-2026-110765.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://hackmd.io/@hieuPenguinnn/flexprice-quickbooks-webhook-signature-bypass

    Supplemental source - technical-description, exploit

  • Source reference

    Unverified legacy reference

    URL: https://github.com/flexprice/flexprice/blob/f27da32f84ee34bad4bf39a8d887af87fc3f30fc/internal/api/v1/webhook.go

    Supplemental source - technical-description

  • Source reference

    Unverified legacy reference

    URL: https://github.com/flexprice/flexprice

    Supplemental source - product

  • Source reference

    Unverified legacy reference

    URL: https://www.vulncheck.com/advisories/flexprice-through-2.1.38-quickbooks-webhook-signature-verification-bypass

    Supplemental source - third-party-advisory

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.