# CVE-2026-121628: Bagisto before 2.3.16 and 2.4.x before 2.4.1 Race Condition in Coupon Usage Accounting

Status: published. Published: 2026-11-03. Updated: 2026-11-03.

Bagisto before 2.3.16 and 2.4.x before 2.4.1 contains a race condition vulnerability in manageCartRule() that allows attackers to redeem single-use coupons multiple times. Attackers can submit concurrent order requests to the onepage orders checkout endpoint, bypassing unlocked times_used checks to apply discounts repeatedly.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/bagisto/bagisto/commit/81cb2a2a35b355492f704fd216d679f2145a5650
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/bagisto/bagisto/commit/1f57c10eb9cb61b37de4706ffa439fd26aa7c405

## Affected products and versions

- bagisto / bagisto (bagisto/bagisto): ≥ 0; < 2.3.16 (affected, semver); ≥ 2.4.0; < 2.4.1 (affected, semver); 2.3.16 (unaffected, semver); 2.4.1 (unaffected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 6.3 (medium); CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 3.7 (low); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N; source: CNA: VulnCheck

- CVSS 4.0: 6.3 (medium); CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 3.7 (low); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-362

## Exploit evidence

- exploit: https://gist.github.com/Ayxpp/5358d9fff045e94e0ddb51677ed5d195 (CNA: VulnCheck)

## References

- https://github.com/bagisto/bagisto/commit/81cb2a2a35b355492f704fd216d679f2145a5650 (CNA: VulnCheck; patch)

- https://github.com/bagisto/bagisto/commit/1f57c10eb9cb61b37de4706ffa439fd26aa7c405 (CNA: VulnCheck; patch)

- https://github.com/bagisto/bagisto/releases/tag/v2.3.16 (CNA: VulnCheck; release-notes)

- https://github.com/bagisto/bagisto/releases/tag/v2.4.1 (CNA: VulnCheck; release-notes)

- https://gist.github.com/Ayxpp/5358d9fff045e94e0ddb51677ed5d195 (CNA: VulnCheck; exploit)

- https://github.com/bagisto/bagisto/blob/v2.4.0/packages/Webkul/CartRule/src/Listeners/Order.php#L30-L95 (CNA: VulnCheck; technical-description)

- https://github.com/bagisto/bagisto (CNA: VulnCheck; product)

- https://www.vulncheck.com/advisories/bagisto-before-2.3.16-and-2.4-x-before-2.4.1-race-condition-in-coupon-usage-accounting (CNA: VulnCheck; third-party-advisory)

- https://gist.github.com/Ayxpp/5358d9fff045e94e0ddb51677ed5d195 (disclosure@vulncheck.com)

- https://github.com/bagisto/bagisto (disclosure@vulncheck.com)

- https://github.com/bagisto/bagisto/blob/v2.4.0/packages/Webkul/CartRule/src/Listeners/Order.php#L30-L95 (disclosure@vulncheck.com)

- https://github.com/bagisto/bagisto/commit/1f57c10eb9cb61b37de4706ffa439fd26aa7c405 (disclosure@vulncheck.com)

- https://github.com/bagisto/bagisto/commit/81cb2a2a35b355492f704fd216d679f2145a5650 (disclosure@vulncheck.com)

- https://github.com/bagisto/bagisto/releases/tag/v2.3.16 (disclosure@vulncheck.com)

- https://github.com/bagisto/bagisto/releases/tag/v2.4.1 (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/bagisto-before-2.3.16-and-2.4-x-before-2.4.1-race-condition-in-coupon-usage-accounting (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-121628; retrieved 2026-11-03; source updated 2026-11-03

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-121628; retrieved 2026-11-04; source updated 2026-11-03

Revision: 718e8123ceb4a777bbf39b634e44ec5fa4125f786ac04b600f06af23de2a9208

Canonical: https://y2.dev/cve/CVE-2026-121628

## Agent and API access

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- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

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