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PatchSiren cyber security CVE debrief

CVE-2026-44826 givanz CVE debrief

CVE-2026-44826 is a high-severity input-validation flaw in Vvveb CMS affecting the cart-add endpoint. Prior to 1.0.8.2, a negative quantity value is accepted and then propagated through cart and checkout calculations, producing negative line totals, subtotals, taxes, and grand totals. The issue can surface in the merchant dashboard as a real order with a negative total, creating an integrity and financial-records problem that normal storefront workflows should never allow.

Vendor
givanz
Product
Vvveb
CVSS
HIGH 7.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-15
Original CVE updated
2026-05-18
Advisory published
2026-05-15
Advisory updated
2026-05-18

Who should care

Vvveb CMS operators, especially merchants running ecommerce storefronts or any deployment exposing the cart-add endpoint, should treat this as important. Site maintainers, hosted service operators, and teams responsible for order integrity or reconciliation should also review affected installations.

Technical summary

The vulnerability is caused by failure to validate the sign of the quantity parameter on the cart-add endpoint. Instead of rejecting negative quantities, the application treats them as normal cart entries and carries the negative sign into downstream calculations. As described in the source, this can lead to negative line-item totals, negative order totals in the checkout flow, and persisted negative totals in the merchant database. NVD records the issue with CVSS 3.1 vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N and currently marks the entry as Deferred.

Defensive priority

High for any internet-facing or production ecommerce deployment of Vvveb CMS. The issue does not require authentication or user interaction and affects order integrity directly, so patching and verification should be prioritized promptly.

Recommended defensive actions

  • Upgrade Vvveb CMS to version 1.0.8.2 or later.
  • Review the cart-add endpoint and enforce server-side validation that rejects negative quantities and other malformed input.
  • Audit existing orders and refunds for negative totals or other anomalous records created before patching.
  • Add monitoring or application checks to flag impossible cart states, such as negative line items or negative grand totals.
  • If immediate patching is not possible, restrict exposure of the storefront and cart functionality while applying compensating controls.
  • Validate that any custom plugins, templates, or API integrations do not bypass the patched server-side quantity checks.

Evidence notes

The source description states that Vvveb CMS prior to 1.0.8.2 does not validate the sign of the quantity parameter on cart-add, and that negative input propagates through totals and persists into merchant order records. The official GitHub advisory link is cited by NVD, and NVD lists the CVSS vector AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N with vulnerability status Deferred. This debrief uses the CVE published date of 2026-05-15 and the modified date of 2026-05-18 from the supplied timeline.

Official resources

Publicly disclosed in the supplied CVE record on 2026-05-15 and modified on 2026-05-18. NVD currently marks the entry as Deferred. The issue is described as fixed in Vvveb CMS 1.0.8.2.