{"cve":"CVE-2026-70658","nvd":{"published":"2026-09-14T18:19:45.213","modified":"2026-09-30T19:09:53.523","status":"Awaiting Analysis","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","score":7.4},"cwes":["CWE-208"],"references":["https://github.com/pay-rails/pay/commit/ba6494109d88209fba2a4df2d9d6373fe81ed805","https://github.com/pay-rails/pay/releases/tag/v11.6.2","https://github.com/pay-rails/pay/security/advisories/GHSA-mjgf-xj26-9qf9","https://github.com/pay-rails/pay/security/advisories/GHSA-mjgf-xj26-9qf9"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:53:43.293028046+00:00"},"epss":{"cve":"CVE-2026-70658","score":0.00578,"percentile":0.47325,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-mjgf-xj26-9qf9","url":"https://osv.dev/vulnerability/GHSA-mjgf-xj26-9qf9","summary":"pay-rails/pay: non-constant-time HMAC comparison in Paddle Billing webhook signature verifier","modified":"2026-09-15T03:56:00.408562725Z","packages":[{"ecosystem":"RubyGems","name":"pay","purl":"pkg:gem/pay","ranges":["<=11.6.1"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}