{"id":"CVE-2026-48747","state":"PUBLISHED","title":"Symfony: Mailomat Mailer Webhook Parser Reads the HMAC Algorithm from the Request: Signature Algorithm Downgrade","description":"Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 7.4.13 and 8.0.13, MailomatRequestParser::validateSignature() parsed X-MOM-Webhook-Signature as algo=signature and passed the request-selected algorithm to hash_hmac(), allowing a signature algorithm downgrade instead of enforcing Mailomat's documented SHA-256 webhook signature. This issue is fixed in versions 7.4.13 and 8.0.13.","publishedAt":"2026-07-14T19:16:24.327Z","updatedAt":"2026-07-15T14:22:53.743Z","severity":{"score":6.3,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:H/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":["symfony symfony","symfony mailomat-mailer"],"affected":[{"vendor":"symfony","product":"symfony","versions":[{"version":">= 7.2.0, < 7.4.12","status":"affected"},{"version":">= 8.0.0-BETA1, < 8.0.13","status":"affected"}]},{"vendor":"symfony","product":"mailomat-mailer","versions":[{"version":">= 7.2.0, < 7.4.12","status":"affected"},{"version":">= 8.0.0-BETA1, < 8.0.13","status":"affected"}]}],"references":["https://github.com/symfony/symfony/security/advisories/GHSA-rrj9-5q2j-4gvr","https://github.com/symfony/symfony/commit/bdfe9fe0d94d33dfaca0bc2fe0b00b54767b0c88","https://github.com/symfony/symfony/releases/tag/v7.4.13","https://github.com/symfony/symfony/releases/tag/v8.0.13"],"weaknesses":["CWE-347","CWE-757"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/48xxx/CVE-2026-48747.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-48747","state":"PUBLISHED","datePublished":"2026-07-14T19:16:24.327Z","dateUpdated":"2026-07-15T14:22:53.743Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-22T19:10:35.747Z"},"containers":{"cna":{"title":"Symfony: Mailomat Mailer Webhook Parser Reads the HMAC Algorithm from the Request: Signature Algorithm Downgrade","descriptions":[{"lang":"en","value":"Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 7.4.13 and 8.0.13, MailomatRequestParser::validateSignature() parsed X-MOM-Webhook-Signature as algo=signature and passed the request-selected algorithm to hash_hmac(), allowing a signature algorithm downgrade instead of enforcing Mailomat's documented SHA-256 webhook signature. This issue is fixed in versions 7.4.13 and 8.0.13."}],"affected":[{"vendor":"symfony","product":"symfony","versions":[{"version":">= 7.2.0, < 7.4.12","status":"affected"},{"version":">= 8.0.0-BETA1, < 8.0.13","status":"affected"}]},{"vendor":"symfony","product":"mailomat-mailer","versions":[{"version":">= 7.2.0, < 7.4.12","status":"affected"},{"version":">= 8.0.0-BETA1, < 8.0.13","status":"affected"}]}],"references":[{"url":"https://github.com/symfony/symfony/security/advisories/GHSA-rrj9-5q2j-4gvr","name":"https://github.com/symfony/symfony/security/advisories/GHSA-rrj9-5q2j-4gvr","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/symfony/symfony/commit/bdfe9fe0d94d33dfaca0bc2fe0b00b54767b0c88","name":"https://github.com/symfony/symfony/commit/bdfe9fe0d94d33dfaca0bc2fe0b00b54767b0c88","tags":["x_refsource_MISC"]},{"url":"https://github.com/symfony/symfony/releases/tag/v7.4.13","name":"https://github.com/symfony/symfony/releases/tag/v7.4.13","tags":["x_refsource_MISC"]},{"url":"https://github.com/symfony/symfony/releases/tag/v8.0.13","name":"https://github.com/symfony/symfony/releases/tag/v8.0.13","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6.3,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:H/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-347","lang":"en","description":"CWE-347: Improper Verification of Cryptographic Signature","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-757","lang":"en","description":"CWE-757: Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-14T19:16:24.327Z"},"source":{"advisory":"GHSA-rrj9-5q2j-4gvr","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-15T14:22:33.134994Z","id":"CVE-2026-48747","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":"2026-07-15T14:22:53.743Z"}}]}}}