CVE-2026-56831: shopperlabs shopper · Improper Input Validation
Affects shopperlabs shopperSource CVE Database V5
Public exploit available · CVSS 6.5 Medium : upgrade to 2.9.0 as a priority.
Data as of 5 Nov 2026, 23:24 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 37% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- Proof of concept is public or traded
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-09-16.
- Patch
- Available – fixed in 2.9.0
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:NExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 15 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CISA SSVC: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by GitHub, Inc.
, 84 days before disclosure
CVE published
on cve.org
, t = 0
CISA SSVC assessment
proof of concept public
, 21 hours after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade shopperlabs shopper to 2.9.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| shopperlabsshopper | Affected
| Fixed in
|
AI-suggested
Upgrade to shopper version 2.9.0 or later, where this issue is fixed by enforcing positive discount values. No additional mitigation is required once the system is updated.
Description
CVE-2026-56831 is an improper input validation vulnerability in shopperlabs shopper versions prior to 2.9.0. The administrative discounts interface accepts negative fixed_amount discount values, which are persisted and used in price calculations without enforcing that discounts be positive. This flaw causes negative discounts to increase order totals instead of reducing them, leading to incorrect pricing and financial data integrity issues. The vulnerability is fixed in version 2.9.0.
References
- github.com/shopperlabs/shopper/security/advisories/GHSA-5vf4-452p-jjhf (opens in a new tab)
- github.com/shopperlabs/shopper/pull/528 (opens in a new tab)
- github.com/shopperlabs/shopper/commit/967e616281ded1a0050d9102858ecd7dd7f66a41 (opens in a new tab)
- github.com/shopperlabs/shopper/releases/tag/v2.9.0 (opens in a new tab)