{"items":[{"id":"NVI-00002118","kind":"vulnerability","title":"The SimpleSAMLphp SAML2 library incorrectly verifies signatures for HTTP-Redirect binding","revision":3,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected.","NVD lastModified does not establish freshness of every associated CPE record."],"lifecycle":"active","identifiers":["GHSA-46r4-f8gj-xg56","CVE-2025-27773"],"plain_summary":"OSV carries this publisher advisory for simplesamlphp/saml2, simplesamlphp/saml2, simplesamlphp/saml2-legacy. This is an aggregated source copy; consult the original publisher and compare update dates.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"The original advisory lists fixed boundaries 4.17.0 for simplesamlphp/saml2. Confirm the publisher’s latest guidance.","source_ids":["sr-0bd4fed15044098ef599cb3a271fa78e"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 5.0.0-alpha.20 for simplesamlphp/saml2. Confirm the publisher’s latest guidance.","source_ids":["sr-0bd4fed15044098ef599cb3a271fa78e"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 4.17.0 for simplesamlphp/saml2-legacy. Confirm the publisher’s latest guidance.","source_ids":["sr-0bd4fed15044098ef599cb3a271fa78e"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-0adaff69b9d90755d7fe575688655206"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-06-17T09:04:11.953Z","value":"8.6 HIGH (3.1)","meaning":"security-advisories@github.com severity; no combined Null risk score.","source_id":"sr-7e7d9605ddf92ac22423e233134ca826"},{"kind":"EPSS","as_of":"2026-11-02T12:00:30.000Z","value":"0.415%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.35796. Missing scores are unknown.","source_id":"sr-0adaff69b9d90755d7fe575688655206"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-0bd4fed15044098ef599cb3a271fa78e","url":"https://github.com/advisories/GHSA-46r4-f8gj-xg56","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-46r4-f8gj-xg56","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:41:49.665Z"},{"id":"sr-7e7d9605ddf92ac22423e233134ca826","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-27773","basis":"official_catalog","notes":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","title":"CVE-2025-27773","publisher":"NIST National Vulnerability Database","observed_at":"2026-11-01T01:39:40.546Z"},{"id":"sr-0adaff69b9d90755d7fe575688655206","url":"https://www.first.org/epss/data.html","basis":"official_catalog","notes":"FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.","title":"CVE-2025-27773","publisher":"FIRST EPSS","observed_at":"2026-11-02T20:15:58.833Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-0bd4fed15044098ef599cb3a271fa78e"],"technology":"simplesamlphp/saml2","known_exclusions":[],"conditions_summary":"### Summary\nThere's a signature confusion attack in the HTTPRedirect binding. An attacker with any signed SAMLResponse via the HTTP-Redirect binding can cause the application to accept an unsigned message.\n\nI believe that it exists for v4 only. I have not yet developed a PoC.\n\nV5 is well designed and instead builds the signed query from the same message that will be consumed.\n### Details\n\n#### What is verified\nThe data['SignedQuery'] is the string that will be verified by the public key. \n\nIt is defined here:\nhttps://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0303e/src/SAML2/HTTPRedirect.php#L178-L217\n\nTHe code will iterate through each parameter name. Notably, sigQuery is overridden each time when processing, making the last of SAMLRequest/SAMLResponse used for sigQuery.\n\nFor example, given:\n\nSAMLRequest=a&SAMLResponse=idpsigned\n\nSAMLResponse=idpsigned will be set as sigQuery, then later verified\n\n\n#### What is actually processed\n\nProcessing uses SAMLRequest parameter value first, (if it exists) then SAMLResponse:\n\nhttps://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0303e/src/SAML2/HTTPRedirect.php#L104-L113\n\nGiven this, the c","public_affected_ranges":["ECOSYSTEM: introduced 0; fixed 4.17.0"]},{"certainty":"source_listed","source_ids":["sr-0bd4fed15044098ef599cb3a271fa78e"],"technology":"simplesamlphp/saml2","known_exclusions":[],"conditions_summary":"### Summary\nThere's a signature confusion attack in the HTTPRedirect binding. An attacker with any signed SAMLResponse via the HTTP-Redirect binding can cause the application to accept an unsigned message.\n\nI believe that it exists for v4 only. I have not yet developed a PoC.\n\nV5 is well designed and instead builds the signed query from the same message that will be consumed.\n### Details\n\n#### What is verified\nThe data['SignedQuery'] is the string that will be verified by the public key. \n\nIt is defined here:\nhttps://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0303e/src/SAML2/HTTPRedirect.php#L178-L217\n\nTHe code will iterate through each parameter name. Notably, sigQuery is overridden each time when processing, making the last of SAMLRequest/SAMLResponse used for sigQuery.\n\nFor example, given:\n\nSAMLRequest=a&SAMLResponse=idpsigned\n\nSAMLResponse=idpsigned will be set as sigQuery, then later verified\n\n\n#### What is actually processed\n\nProcessing uses SAMLRequest parameter value first, (if it exists) then SAMLResponse:\n\nhttps://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0303e/src/SAML2/HTTPRedirect.php#L104-L113\n\nGiven this, the c","public_affected_ranges":["ECOSYSTEM: introduced 5.0.0-alpha.1; fixed 5.0.0-alpha.20"]},{"certainty":"source_listed","source_ids":["sr-0bd4fed15044098ef599cb3a271fa78e"],"technology":"simplesamlphp/saml2-legacy","known_exclusions":[],"conditions_summary":"### Summary\nThere's a signature confusion attack in the HTTPRedirect binding. An attacker with any signed SAMLResponse via the HTTP-Redirect binding can cause the application to accept an unsigned message.\n\nI believe that it exists for v4 only. I have not yet developed a PoC.\n\nV5 is well designed and instead builds the signed query from the same message that will be consumed.\n### Details\n\n#### What is verified\nThe data['SignedQuery'] is the string that will be verified by the public key. \n\nIt is defined here:\nhttps://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0303e/src/SAML2/HTTPRedirect.php#L178-L217\n\nTHe code will iterate through each parameter name. Notably, sigQuery is overridden each time when processing, making the last of SAMLRequest/SAMLResponse used for sigQuery.\n\nFor example, given:\n\nSAMLRequest=a&SAMLResponse=idpsigned\n\nSAMLResponse=idpsigned will be set as sigQuery, then later verified\n\n\n#### What is actually processed\n\nProcessing uses SAMLRequest parameter value first, (if it exists) then SAMLResponse:\n\nhttps://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0303e/src/SAML2/HTTPRedirect.php#L104-L113\n\nGiven this, the c","public_affected_ranges":["ECOSYSTEM: introduced 0; fixed 4.17.0"]}],"null_published_at":"2026-11-03T17:49:21.348Z","source_updated_at":"2026-09-10T03:50:56.811Z","source_disclosed_at":"2025-03-11T19:23:22.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-10-31T21:41:49.665Z"},{"id":"NVI-00002118","kind":"vulnerability","title":"The SimpleSAMLphp SAML2 library incorrectly verifies signatures for HTTP-Redirect binding","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-46r4-f8gj-xg56","CVE-2025-27773"],"plain_summary":"OSV carries this publisher advisory for simplesamlphp/saml2, simplesamlphp/saml2, simplesamlphp/saml2-legacy. This is an aggregated source copy; consult the original publisher and compare update dates.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"The original advisory lists fixed boundaries 4.17.0 for simplesamlphp/saml2. Confirm the publisher’s latest guidance.","source_ids":["sr-0bd4fed15044098ef599cb3a271fa78e"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 5.0.0-alpha.20 for simplesamlphp/saml2. Confirm the publisher’s latest guidance.","source_ids":["sr-0bd4fed15044098ef599cb3a271fa78e"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null},{"summary":"The original advisory lists fixed boundaries 4.17.0 for simplesamlphp/saml2-legacy. Confirm the publisher’s latest guidance.","source_ids":["sr-0bd4fed15044098ef599cb3a271fa78e"],"action_type":"vendor_patch","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-0bd4fed15044098ef599cb3a271fa78e","url":"https://github.com/advisories/GHSA-46r4-f8gj-xg56","basis":"vendor_advisory","notes":"GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.","title":"GHSA-46r4-f8gj-xg56","publisher":"GitHub Advisory Database via OSV","observed_at":"2026-10-31T21:41:49.665Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-0bd4fed15044098ef599cb3a271fa78e"],"technology":"simplesamlphp/saml2","known_exclusions":[],"conditions_summary":"### Summary\nThere's a signature confusion attack in the HTTPRedirect binding. An attacker with any signed SAMLResponse via the HTTP-Redirect binding can cause the application to accept an unsigned message.\n\nI believe that it exists for v4 only. I have not yet developed a PoC.\n\nV5 is well designed and instead builds the signed query from the same message that will be consumed.\n### Details\n\n#### What is verified\nThe data['SignedQuery'] is the string that will be verified by the public key. \n\nIt is defined here:\nhttps://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0303e/src/SAML2/HTTPRedirect.php#L178-L217\n\nTHe code will iterate through each parameter name. Notably, sigQuery is overridden each time when processing, making the last of SAMLRequest/SAMLResponse used for sigQuery.\n\nFor example, given:\n\nSAMLRequest=a&SAMLResponse=idpsigned\n\nSAMLResponse=idpsigned will be set as sigQuery, then later verified\n\n\n#### What is actually processed\n\nProcessing uses SAMLRequest parameter value first, (if it exists) then SAMLResponse:\n\nhttps://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0303e/src/SAML2/HTTPRedirect.php#L104-L113\n\nGiven this, the c","public_affected_ranges":["ECOSYSTEM: introduced 0; fixed 4.17.0"]},{"certainty":"source_listed","source_ids":["sr-0bd4fed15044098ef599cb3a271fa78e"],"technology":"simplesamlphp/saml2","known_exclusions":[],"conditions_summary":"### Summary\nThere's a signature confusion attack in the HTTPRedirect binding. An attacker with any signed SAMLResponse via the HTTP-Redirect binding can cause the application to accept an unsigned message.\n\nI believe that it exists for v4 only. I have not yet developed a PoC.\n\nV5 is well designed and instead builds the signed query from the same message that will be consumed.\n### Details\n\n#### What is verified\nThe data['SignedQuery'] is the string that will be verified by the public key. \n\nIt is defined here:\nhttps://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0303e/src/SAML2/HTTPRedirect.php#L178-L217\n\nTHe code will iterate through each parameter name. Notably, sigQuery is overridden each time when processing, making the last of SAMLRequest/SAMLResponse used for sigQuery.\n\nFor example, given:\n\nSAMLRequest=a&SAMLResponse=idpsigned\n\nSAMLResponse=idpsigned will be set as sigQuery, then later verified\n\n\n#### What is actually processed\n\nProcessing uses SAMLRequest parameter value first, (if it exists) then SAMLResponse:\n\nhttps://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0303e/src/SAML2/HTTPRedirect.php#L104-L113\n\nGiven this, the c","public_affected_ranges":["ECOSYSTEM: introduced 5.0.0-alpha.1; fixed 5.0.0-alpha.20"]},{"certainty":"source_listed","source_ids":["sr-0bd4fed15044098ef599cb3a271fa78e"],"technology":"simplesamlphp/saml2-legacy","known_exclusions":[],"conditions_summary":"### Summary\nThere's a signature confusion attack in the HTTPRedirect binding. An attacker with any signed SAMLResponse via the HTTP-Redirect binding can cause the application to accept an unsigned message.\n\nI believe that it exists for v4 only. I have not yet developed a PoC.\n\nV5 is well designed and instead builds the signed query from the same message that will be consumed.\n### Details\n\n#### What is verified\nThe data['SignedQuery'] is the string that will be verified by the public key. \n\nIt is defined here:\nhttps://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0303e/src/SAML2/HTTPRedirect.php#L178-L217\n\nTHe code will iterate through each parameter name. Notably, sigQuery is overridden each time when processing, making the last of SAMLRequest/SAMLResponse used for sigQuery.\n\nFor example, given:\n\nSAMLRequest=a&SAMLResponse=idpsigned\n\nSAMLResponse=idpsigned will be set as sigQuery, then later verified\n\n\n#### What is actually processed\n\nProcessing uses SAMLRequest parameter value first, (if it exists) then SAMLResponse:\n\nhttps://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0303e/src/SAML2/HTTPRedirect.php#L104-L113\n\nGiven this, the c","public_affected_ranges":["ECOSYSTEM: introduced 0; fixed 4.17.0"]}],"null_published_at":"2026-10-31T21:53:28.065Z","source_updated_at":"2026-09-10T03:50:56.811Z","source_disclosed_at":"2025-03-11T19:23:22.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-10-31T21:41:49.665Z"}],"next_cursor":null,"snapshot_revision":"42594"}