{"id":"CVE-2026-70658","state":"PUBLISHED","title":"pay-rails/pay: non-constant-time HMAC comparison in Paddle Billing webhook signature verifier","description":"Pay is a payments engine for Ruby on Rails 6.0 and higher. Prior to 11.6.2, Pay::Webhooks::PaddleBillingController#valid_signature? in app/controllers/pay/webhooks/paddle_billing_controller.rb compares the computed 64-character SHA-256 HMAC with the attacker-controlled h1 token from the Paddle-Signature header using Ruby String#==. An unauthenticated remote attacker who can repeatedly submit requests to /pay/webhooks/paddle_billing and obtain sufficiently precise timing measurements can infer matching digest prefixes and recover a valid signature. A forged accepted webhook is enqueued through Pay::Webhooks::ProcessJob and can cause a host application to update billing state, provision paid features, record refunds, or trigger customer notifications. This issue is fixed in version 11.6.2.","publishedAt":"2026-09-14T17:14:57.207Z","updatedAt":"2026-09-14T18:57:30.947Z","severity":{"score":7.4,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["pay-rails pay"],"affected":[{"vendor":"pay-rails","product":"pay","versions":[{"version":"< 11.6.2","status":"affected"}]}],"references":["https://github.com/pay-rails/pay/security/advisories/GHSA-mjgf-xj26-9qf9","https://github.com/pay-rails/pay/commit/ba6494109d88209fba2a4df2d9d6373fe81ed805","https://github.com/pay-rails/pay/releases/tag/v11.6.2"],"weaknesses":["CWE-208"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/70xxx/CVE-2026-70658.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-70658","state":"PUBLISHED","datePublished":"2026-09-14T17:14:57.207Z","dateUpdated":"2026-09-14T18:57:30.947Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-08-04T21:48:08.613Z"},"containers":{"cna":{"title":"pay-rails/pay: non-constant-time HMAC comparison in Paddle Billing webhook signature verifier","descriptions":[{"lang":"en","value":"Pay is a payments engine for Ruby on Rails 6.0 and higher. Prior to 11.6.2, Pay::Webhooks::PaddleBillingController#valid_signature? in app/controllers/pay/webhooks/paddle_billing_controller.rb compares the computed 64-character SHA-256 HMAC with the attacker-controlled h1 token from the Paddle-Signature header using Ruby String#==. An unauthenticated remote attacker who can repeatedly submit requests to /pay/webhooks/paddle_billing and obtain sufficiently precise timing measurements can infer matching digest prefixes and recover a valid signature. A forged accepted webhook is enqueued through Pay::Webhooks::ProcessJob and can cause a host application to update billing state, provision paid features, record refunds, or trigger customer notifications. This issue is fixed in version 11.6.2."}],"affected":[{"vendor":"pay-rails","product":"pay","versions":[{"version":"< 11.6.2","status":"affected"}]}],"references":[{"url":"https://github.com/pay-rails/pay/security/advisories/GHSA-mjgf-xj26-9qf9","name":"https://github.com/pay-rails/pay/security/advisories/GHSA-mjgf-xj26-9qf9","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/pay-rails/pay/commit/ba6494109d88209fba2a4df2d9d6373fe81ed805","name":"https://github.com/pay-rails/pay/commit/ba6494109d88209fba2a4df2d9d6373fe81ed805","tags":["x_refsource_MISC"]},{"url":"https://github.com/pay-rails/pay/releases/tag/v11.6.2","name":"https://github.com/pay-rails/pay/releases/tag/v11.6.2","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.4,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-208","lang":"en","description":"CWE-208: Observable Timing Discrepancy","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-14T17:14:57.207Z"},"source":{"advisory":"GHSA-mjgf-xj26-9qf9","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/pay-rails/pay/security/advisories/GHSA-mjgf-xj26-9qf9","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-14T18:57:23.905589Z","id":"CVE-2026-70658","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-14T18:57:30.947Z"}}]}}}