{"id":"CVE-2026-43927","state":"PUBLISHED","title":"FOSSBilling has race condition in cart checkout that bypasses promo code usage limits","description":"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.","publishedAt":"2026-07-06T21:49:26.181Z","updatedAt":"2026-07-07T12:47:00.755Z","severity":{"score":6.9,"label":"Medium","version":"4.0","vector":"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","source":"GitHub_M"},"assigner":"GitHub_M","products":["FOSSBilling FOSSBilling"],"affected":[{"vendor":"FOSSBilling","product":"FOSSBilling","versions":[{"version":"< 0.8.0","status":"affected"}]}],"references":["https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-w898-cx35-25gh"],"weaknesses":["CWE-367"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43927.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43927","state":"PUBLISHED","datePublished":"2026-07-06T21:49:26.181Z","dateUpdated":"2026-07-07T12:47:00.755Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-04T16:59:09.089Z"},"containers":{"cna":{"title":"FOSSBilling has race condition in cart checkout that bypasses promo code usage limits","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"FOSSBilling","product":"FOSSBilling","versions":[{"version":"< 0.8.0","status":"affected"}]}],"references":[{"url":"https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-w898-cx35-25gh","name":"https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-w898-cx35-25gh","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6.9,"baseSeverity":"MEDIUM","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-367","lang":"en","description":"CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-06T21:49:26.181Z"},"source":{"advisory":"GHSA-w898-cx35-25gh","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-07T12:46:52.345735Z","id":"CVE-2026-43927","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-07T12:47:00.755Z"}}]}}}