CVE-2026-113603

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-113603", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-10-20T11:48:49.343Z", "datePublished": "2026-10-20T15:40:30.742Z", "dateUpdated": "2026-10-21T15:54:28.895Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-10-20T15:40:30.742Z"}, "datePublic": "2026-10-17T12:38:29.000Z", "title": "x402 @x402/extensions 2.3.1 through 2.28.0 SIWX Payment Bypass via PaymentPayload.resource", "descriptions": [{"lang": "en", "value": "The x402 SIWX server extension in @x402/extensions 2.3.1 through 2.28.0, x402 PyPI 2.11.0 through 2.25.0, and Go module 2.16.0 through 2.28.0 contains an authorization bypass vulnerability that allows paying clients to unlock unpaid routes by supplying a mismatched PaymentPayload.resource URL. Attackers can pay for the cheapest SIWX-protected route while setting resource.url to an expensive route, then repeatedly access it using only a SIGN-IN-WITH-X header without further payment."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Authorization Bypass Through User-Controlled Key", "cweId": "CWE-639", "type": "CWE"}]}], "affected": [{"vendor": "x402-foundation", "product": "@x402/extensions", "defaultStatus": "unaffected", "versions": [{"version": "2.3.1", "lessThanOrEqual": "2.28.0", "status": "affected", "versionType": "semver"}], "packageURL": "pkg:npm/%40x402/extensions", "repo": "https://github.com/x402-foundation/x402"}, {"vendor": "x402-foundation", "product": "x402", "defaultStatus": "unaffected", "versions": [{"version": "2.11.0", "lessThanOrEqual": "2.25.0", "status": "affected", "versionType": "semver"}], "repo": "https://github.com/x402-foundation/x402", "packageURL": "pkg:pypi/x402"}, {"vendor": "x402-foundation", "product": "github.com/x402-foundation/x402/go/v2", "defaultStatus": "unaffected", "versions": [{"version": "2.16.0", "lessThanOrEqual": "2.28.0", "status": "affected", "versionType": "semver"}], "repo": "https://github.com/x402-foundation/x402", "packageURL": "pkg:golang/github.com/x402-foundation/x402/go/v2"}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 6.9, "baseSeverity": "MEDIUM"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE", "baseScore": 6.5, "baseSeverity": "MEDIUM"}}], "references": [{"url": "https://github.com/x402-foundation/x402/issues/3838", "tags": ["issue-tracking"]}, {"url": "https://github.com/x402-foundation/x402/pull/3840", "tags": ["patch", "issue-tracking"]}, {"url": "https://github.com/x402-foundation/x402/blob/npm-@x402/extensions@v2.28.0/typescript/packages/extensions/src/sign-in-with-x/hooks.ts", "tags": ["technical-description"]}, {"url": "https://github.com/x402-foundation/x402/blob/pypi-x402@v2.25.0/python/x402/extensions/sign_in_with_x/hooks.py", "tags": ["technical-description"]}, {"url": "https://github.com/x402-foundation/x402/blob/go/v2.28.0/go/extensions/signinwithx/server.go", "tags": ["technical-description"]}, {"name": "VulnCheck Advisory: x402 @x402/extensions 2.3.1 through 2.28.0 SIWX Payment Bypass via PaymentPayload.resource", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/x402-x402-extensions-2.3.1-through-2.28.0-siwx-payment-bypass-via-paymentpayload-resource"}], "credits": [{"lang": "en", "value": "CBF, Lza", "type": "finder"}], "x_generator": {"engine": "vulncheck-endgame"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-10-21T14:40:26.284069Z", "id": "CVE-2026-113603", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-21T15:54:28.895Z"}}]}}

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-113603", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-10-20T11:48:49.343Z", "datePublished": "2026-10-20T15:40:30.742Z", "dateUpdated": "2026-10-21T15:54:28.895Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-10-20T15:40:30.742Z"}, "datePublic": "2026-10-17T12:38:29.000Z", "title": "x402 @x402/extensions 2.3.1 through 2.28.0 SIWX Payment Bypass via PaymentPayload.resource", "descriptions": [{"lang": "en", "value": "The x402 SIWX server extension in @x402/extensions 2.3.1 through 2.28.0, x402 PyPI 2.11.0 through 2.25.0, and Go module 2.16.0 through 2.28.0 contains an authorization bypass vulnerability that allows paying clients to unlock unpaid routes by supplying a mismatched PaymentPayload.resource URL. Attackers can pay for the cheapest SIWX-protected route while setting resource.url to an expensive route, then repeatedly access it using only a SIGN-IN-WITH-X header without further payment."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Authorization Bypass Through User-Controlled Key", "cweId": "CWE-639", "type": "CWE"}]}], "affected": [{"vendor": "x402-foundation", "product": "@x402/extensions", "defaultStatus": "unaffected", "versions": [{"version": "2.3.1", "lessThanOrEqual": "2.28.0", "status": "affected", "versionType": "semver"}], "packageURL": "pkg:npm/%40x402/extensions", "repo": "https://github.com/x402-foundation/x402"}, {"vendor": "x402-foundation", "product": "x402", "defaultStatus": "unaffected", "versions": [{"version": "2.11.0", "lessThanOrEqual": "2.25.0", "status": "affected", "versionType": "semver"}], "repo": "https://github.com/x402-foundation/x402", "packageURL": "pkg:pypi/x402"}, {"vendor": "x402-foundation", "product": "github.com/x402-foundation/x402/go/v2", "defaultStatus": "unaffected", "versions": [{"version": "2.16.0", "lessThanOrEqual": "2.28.0", "status": "affected", "versionType": "semver"}], "repo": "https://github.com/x402-foundation/x402", "packageURL": "pkg:golang/github.com/x402-foundation/x402/go/v2"}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 6.9, "baseSeverity": "MEDIUM"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE", "baseScore": 6.5, "baseSeverity": "MEDIUM"}}], "references": [{"url": "https://github.com/x402-foundation/x402/issues/3838", "tags": ["issue-tracking"]}, {"url": "https://github.com/x402-foundation/x402/pull/3840", "tags": ["patch", "issue-tracking"]}, {"url": "https://github.com/x402-foundation/x402/blob/npm-@x402/extensions@v2.28.0/typescript/packages/extensions/src/sign-in-with-x/hooks.ts", "tags": ["technical-description"]}, {"url": "https://github.com/x402-foundation/x402/blob/pypi-x402@v2.25.0/python/x402/extensions/sign_in_with_x/hooks.py", "tags": ["technical-description"]}, {"url": "https://github.com/x402-foundation/x402/blob/go/v2.28.0/go/extensions/signinwithx/server.go", "tags": ["technical-description"]}, {"name": "VulnCheck Advisory: x402 @x402/extensions 2.3.1 through 2.28.0 SIWX Payment Bypass via PaymentPayload.resource", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/x402-x402-extensions-2.3.1-through-2.28.0-siwx-payment-bypass-via-paymentpayload-resource"}], "credits": [{"lang": "en", "value": "CBF, Lza", "type": "finder"}], "x_generator": {"engine": "vulncheck-endgame"}}, "adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-113603", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-21T14:40:26.284069Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-21T14:40:26.987Z"}}]}}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "packageURL": "pkg:npm/%40x402/extensions", "product": "@x402/extensions", "repo": "https://github.com/x402-foundation/x402", "vendor": "x402-foundation", "versions": [{"lessThanOrEqual": "2.28.0", "status": "affected", "version": "2.3.1", "versionType": "semver"}]}, {"defaultStatus": "unaffected", "packageURL": "pkg:pypi/x402", "product": "x402", "repo": "https://github.com/x402-foundation/x402", "vendor": "x402-foundation", "versions": [{"lessThanOrEqual": "2.25.0", "status": "affected", "version": "2.11.0", "versionType": "semver"}]}, {"defaultStatus": "unaffected", "packageURL": "pkg:golang/github.com/x402-foundation/x402/go/v2", "product": "github.com/x402-foundation/x402/go/v2", "repo": "https://github.com/x402-foundation/x402", "vendor": "x402-foundation", "versions": [{"lessThanOrEqual": "2.28.0", "status": "affected", "version": "2.16.0", "versionType": "semver"}]}], "source": "disclosure@vulncheck.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "The x402 SIWX server extension in @x402/extensions 2.3.1 through 2.28.0, x402 PyPI 2.11.0 through 2.25.0, and Go module 2.16.0 through 2.28.0 contains an authorization bypass vulnerability that allows paying clients to unlock unpaid routes by supplying a mismatched PaymentPayload.resource URL. Attackers can pay for the cheapest SIWX-protected route while setting resource.url to an expensive route, then repeatedly access it using only a SIGN-IN-WITH-X header without further payment."}], "id": "CVE-2026-113603", "lastModified": "2026-10-21T16:17:23.530", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 2.5, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.9, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-113603", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-10-21T14:40:26.284069Z", "version": "2.0.3"}}]}, "published": "2026-10-20T16:17:10.087", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/x402-foundation/x402/blob/go/v2.28.0/go/extensions/signinwithx/server.go"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/x402-foundation/x402/blob/npm-@x402/extensions@v2.28.0/typescript/packages/extensions/src/sign-in-with-x/hooks.ts"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/x402-foundation/x402/blob/pypi-x402@v2.25.0/python/x402/extensions/sign_in_with_x/hooks.py"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/x402-foundation/x402/issues/3838"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/x402-foundation/x402/pull/3840"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/x402-x402-extensions-2.3.1-through-2.28.0-siwx-payment-bypass-via-paymentpayload-resource"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-639"}], "source": "disclosure@vulncheck.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[2.3.1,2.28.0]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "manual", "scores": [{"score": 100.0, "source": "manual"}]}, "original": {"product": "@x402/extensions", "source": "cna", "vendor": "x402-foundation"}, "product": "x402", "vendor": "x402-foundation"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[2.11.0,2.25.0]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "cna", "scores": [{"score": 100.0, "source": "cna"}]}, "original": {"product": "x402", "source": "cna", "vendor": "x402-foundation"}, "product": "x402", "vendor": "x402-foundation"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[2.16.0,2.28.0]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "manual", "scores": [{"score": 100.0, "source": "manual"}]}, "original": {"product": "github.com/x402-foundation/x402/go/v2", "source": "cna", "vendor": "x402-foundation"}, "product": "x402", "vendor": "x402-foundation"}], "created": "2026-10-20T17:30:13.830903+00:00", "updated": "2026-10-21T16:44:31.534305+00:00", "vendors": ["x402-foundation", "x402-foundation$PRODUCT$x402"]}