{"id":"CVE-2026-43927","summary":"FOSSBilling has race condition in cart checkout that bypasses promo code usage limits","details":"FOSSBilling is a free, open-source billing and client management system. Prior to version 0.8.0, a race condition in the cart checkout flow allows an authenticated client to apply a promo code beyond its configured maximum uses. By sending concurrent checkout requests before any single request completes the usage increment, a client can obtain unlimited discounted or free orders from a single-use or limited-use promo code. Version 0.8.0 patches the issue. Some workarounds are available. Disable promo codes entirely until a patch is available or monitor the `promo` table for `used` values exceeding `maxuses` and manually review affected orders.","aliases":["GHSA-w898-cx35-25gh"],"modified":"2026-07-15T01:48:50.354292285Z","published":"2026-07-06T21:49:26.181Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43927.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-367"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43927.json"},{"type":"ADVISORY","url":"https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-w898-cx35-25gh"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43927"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/fossbilling/fossbilling","events":[{"introduced":"0"},{"fixed":"3bd35f5b2921d8a26a403142ae0408f95e6463cc"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"0.8.0"}],"source":"AFFECTED_FIELD"}}],"versions":["0.7.2","0.7.1","0.7.0","0.6.22","0.6.21","0.6.20","0.6.19","0.6.18","0.6.17","0.6.16","0.6.15","0.6.14","0.6.13","0.6.12","0.6.11","0.6.10","0.6.9","0.6.8","0.6.7","0.6.6","0.6.5","0.6.4","0.6.3","0.6.2","0.6.1","0.6.0","0.5.5","0.5.4","0.5.3","0.5.2","0.5.1","0.5.0","0.4.3","0.4.2","0.4.1","0.4.0","0.3.0","0.2.10","0.2.9","0.2.8","0.2.7","0.2.6","0.2.5","0.2.4","0.2.3","0.2.2","0.2.1","0.2.0","0.1.1","0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43927.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N"}]}