CVE-2021-26631Network attack vector

Order-total manipulation via negative quantity parameter

Published May 19, 2022 · Updated Aug 3, 2024

Improper input validation in Hometory MangBoard Commerce Package 1.3.8 and earlier allows remote attackers to alter order totals via crafted quantities. The cart handler in mangboard/api/mb-commerce.php accepts a negative product-quantity parameter and uses it to calculate a total below zero. Submitting the altered cart request is sufficient to complete an order and payment at the invalid amount without prior authentication.

CVSS severity7.5
High
EPSS probability1.01%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Hometory MangBoard Commerce Package 1.3.8 and earlier allows remote attackers to alter order totals via crafted quantities. The cart handler in mangboard/api/mb-commerce.php accepts a negative product-quantity parameter and uses it to calculate a total below zero. Submitting the altered cart request is sufficient to complete an order and payment at the invalid amount without prior authentication.

The record

CVE
CVE-2021-26631
Published
May 19, 2022
Updated
Aug 3, 2024
Vendor
Hometory
Product
MangBoard Commerce Package
Classifications
CWE-20, T1565.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 19, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <=1.3.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Hometory · MangBoard Commerce Packageversion=unspecified <=1.3.8

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
8.0KrCERT/CCCVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1565.003Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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