CVE-2026-40458

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-40458", "assignerOrgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6", "state": "PUBLISHED", "assignerShortName": "CERT-PL", "dateReserved": "2026-04-13T10:06:07.141Z", "datePublished": "2026-04-17T13:18:26.308Z", "dateUpdated": "2026-04-17T14:00:04.811Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "product": "PAC4J", "vendor": "PAC4J", "versions": [{"lessThan": "5.7.10", "status": "affected", "version": "5.0", "versionType": "semver"}, {"lessThan": "6.4.1", "status": "affected", "version": "6.0", "versionType": "semver"}]}], "credits": [{"lang": "en", "type": "finder", "value": "Bart\u0142omiej Dmitruk, striga.ai"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "PAC4J is vulnerable to Cross-Site Request Forgery (CSRF). A malicious attacker can craft a specially designed website which, when visited by a user, will automatically submit a forged cross-site request with a token whose hash collides with the victim's legitimate CSRF token. Importantly, the attacker does not need to know the victim\u2019s CSRF token or its hash prior to the attack. Collisions in the deterministic String.hashCode() function can be computed directly, reducing the effective token's security space to 32 bits. This bypasses CSRF protection, allowing profile updates, password changes, account linking, and any other state-changing operations to be performed without the victim's consent.<br><br>This issue was fixed in&nbsp;PAC4J versions 5.7.10 and&nbsp;6.4.1<br>"}], "value": "PAC4J is vulnerable to Cross-Site Request Forgery (CSRF). A malicious attacker can craft a specially designed website which, when visited by a user, will automatically submit a forged cross-site request with a token whose hash collides with the victim's legitimate CSRF token. Importantly, the attacker does not need to know the victim\u2019s CSRF token or its hash prior to the attack. Collisions in the deterministic String.hashCode() function can be computed directly, reducing the effective token's security space to 32 bits. This bypasses CSRF protection, allowing profile updates, password changes, account linking, and any other state-changing operations to be performed without the victim's consent.\n\nThis issue was fixed in\u00a0PAC4J versions 5.7.10 and\u00a06.4.1"}], "impacts": [{"capecId": "CAPEC-62", "descriptions": [{"lang": "en", "value": "CAPEC-62 Cross Site Request Forgery"}]}], "metrics": [{"cvssV4_0": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "baseScore": 7, "baseSeverity": "HIGH", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "ACTIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N", "version": "4.0", "vulnAvailabilityImpact": "LOW", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-352", "description": "CWE-352 Cross-Site Request Forgery (CSRF)", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6", "shortName": "CERT-PL", "dateUpdated": "2026-04-17T13:18:26.308Z"}, "references": [{"tags": ["third-party-advisory"], "url": "https://cert.pl/en/posts/2026/04/CVE-2026-40458/"}, {"tags": ["vendor-advisory"], "url": "https://www.pac4j.org/blog/security-advisory-pac4j-core-and-ldap.html"}], "source": {"discovery": "EXTERNAL"}, "title": "Cross-Site Request Forgery in PAC4J", "x_generator": {"engine": "Vulnogram 0.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-04-17T13:57:28.263723Z", "id": "CVE-2026-40458", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"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": "2026-04-17T14:00:04.811Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-40458", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-04-17T13:57:28.263723Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-04-17T13:59:26.592Z"}}], "cna": {"title": "Cross-Site Request Forgery in PAC4J", "source": {"discovery": "EXTERNAL"}, "credits": [{"lang": "en", "type": "finder", "value": "Bart\u0142omiej Dmitruk, striga.ai"}], "impacts": [{"capecId": "CAPEC-62", "descriptions": [{"lang": "en", "value": "CAPEC-62 Cross Site Request Forgery"}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 7, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N", "providerUrgency": "NOT_DEFINED", "userInteraction": "ACTIVE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "affected": [{"vendor": "PAC4J", "product": "PAC4J", "versions": [{"status": "affected", "version": "5.0", "lessThan": "5.7.10", "versionType": "semver"}, {"status": "affected", "version": "6.0", "lessThan": "6.4.1", "versionType": "semver"}], "defaultStatus": "unaffected"}], "references": [{"url": "https://cert.pl/en/posts/2026/04/CVE-2026-40458/", "tags": ["third-party-advisory"]}, {"url": "https://www.pac4j.org/blog/security-advisory-pac4j-core-and-ldap.html", "tags": ["vendor-advisory"]}], "x_generator": {"engine": "Vulnogram 0.2.0"}, "descriptions": [{"lang": "en", "value": "PAC4J is vulnerable to Cross-Site Request Forgery (CSRF). A malicious attacker can craft a specially designed website which, when visited by a user, will automatically submit a forged cross-site request with a token whose hash collides with the victim's legitimate CSRF token. Importantly, the attacker does not need to know the victim\u2019s CSRF token or its hash prior to the attack. Collisions in the deterministic String.hashCode() function can be computed directly, reducing the effective token's security space to 32 bits. This bypasses CSRF protection, allowing profile updates, password changes, account linking, and any other state-changing operations to be performed without the victim's consent.\n\nThis issue was fixed in\u00a0PAC4J versions 5.7.10 and\u00a06.4.1", "supportingMedia": [{"type": "text/html", "value": "PAC4J is vulnerable to Cross-Site Request Forgery (CSRF). A malicious attacker can craft a specially designed website which, when visited by a user, will automatically submit a forged cross-site request with a token whose hash collides with the victim's legitimate CSRF token. Importantly, the attacker does not need to know the victim\u2019s CSRF token or its hash prior to the attack. Collisions in the deterministic String.hashCode() function can be computed directly, reducing the effective token's security space to 32 bits. This bypasses CSRF protection, allowing profile updates, password changes, account linking, and any other state-changing operations to be performed without the victim's consent.<br><br>This issue was fixed in&nbsp;PAC4J versions 5.7.10 and&nbsp;6.4.1<br>", "base64": false}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-352", "description": "CWE-352 Cross-Site Request Forgery (CSRF)"}]}], "providerMetadata": {"orgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6", "shortName": "CERT-PL", "dateUpdated": "2026-04-17T13:18:26.308Z"}}}, "cveMetadata": {"cveId": "CVE-2026-40458", "state": "PUBLISHED", "dateUpdated": "2026-04-17T14:00:04.811Z", "dateReserved": "2026-04-13T10:06:07.141Z", "assignerOrgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6", "datePublished": "2026-04-17T13:18:26.308Z", "assignerShortName": "CERT-PL"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "PAC4J", "vendor": "PAC4J", "versions": [{"lessThan": "5.7.10", "status": "affected", "version": "5.0", "versionType": "semver"}, {"lessThan": "6.4.1", "status": "affected", "version": "6.0", "versionType": "semver"}]}], "source": "cvd@cert.pl"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:pac4j:pac4j:*:*:*:*:*:*:*:*", "matchCriteriaId": "0A9A7C72-1A3D-4386-8324-D31767E591E7", "versionEndExcluding": "5.7.10", "versionStartIncluding": "5.0.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:pac4j:pac4j:*:*:*:*:*:*:*:*", "matchCriteriaId": "7B0B5830-EE4D-47E9-A0A2-667C0149F562", "versionEndExcluding": "6.4.1", "versionStartExcluding": "6.0.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "PAC4J is vulnerable to Cross-Site Request Forgery (CSRF). A malicious attacker can craft a specially designed website which, when visited by a user, will automatically submit a forged cross-site request with a token whose hash collides with the victim's legitimate CSRF token. Importantly, the attacker does not need to know the victim\u2019s CSRF token or its hash prior to the attack. Collisions in the deterministic String.hashCode() function can be computed directly, reducing the effective token's security space to 32 bits. This bypasses CSRF protection, allowing profile updates, password changes, account linking, and any other state-changing operations to be performed without the victim's consent.\n\nThis issue was fixed in\u00a0PAC4J versions 5.7.10 and\u00a06.4.1"}], "id": "CVE-2026-40458", "lastModified": "2026-06-17T10:45:19.557", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 7.0, "baseSeverity": "HIGH", "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": "ACTIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:L/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": "LOW", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "cvd@cert.pl", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-40458", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-04-17T13:57:28.263723Z", "version": "2.0.3"}}]}, "published": "2026-04-17T14:16:33.987", "references": [{"source": "cvd@cert.pl", "tags": ["Third Party Advisory"], "url": "https://cert.pl/en/posts/2026/04/CVE-2026-40458/"}, {"source": "cvd@cert.pl", "tags": ["Vendor Advisory"], "url": "https://www.pac4j.org/blog/security-advisory-pac4j-core-and-ldap.html"}], "sourceIdentifier": "cvd@cert.pl", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-352"}], "source": "cvd@cert.pl", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[5.0,5.7.10)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.0,6.4.1)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "PAC4J", "source": "cna", "vendor": "PAC4J"}, "product": "pac4j", "vendor": "pac4j"}], "analysis": {"en": {"generated_at": "2026-04-18T09:18:31.914573+00:00", "value": {"mitigation_remediation": ["Upgrade PAC4J to version 5.7.10 or newer.", "If upgrading to 6.4.1, verify that the application\u2019s configuration and authentication flows remain compatible.", "If an immediate upgrade is not possible, disable the CSRF protection or replace the deterministic token generation until a patched version is deployed."], "summary": {"action": "Apply Patch", "impact": "Cross\u2011Site Request Forgery leading to unauthorized state changes"}, "threat_synthesis": {"affected_systems": "PAC4J versions earlier than 5.7.10 and 6.4.1 are affected. The vulnerability has been addressed in PAC4J 5.7.10 and 6.4.1, so all users running older releases are at risk.", "description_and_impact": "PAC4J is vulnerable to a Cross\u2011Site Request Forgery (CSRF) flaw that allows an attacker to create a malicious web page which automatically submits a forged request to a target application. By exploiting a collision in Java\u2019s deterministic String.hashCode() function, the attacker can generate a token whose hash matches the victim\u2019s legitimate CSRF token without knowing the token itself, effectively reducing the token space to 32 bits. This enables the attacker to trigger profile updates, password changes, account linkage, and other state\u2011changing operations without the user\u2019s consent.", "risk_and_exploitability": "The CVSS score is 7 indicating a high severity level, and the exploitability is high because the attacker does not need to learn the victim\u2019s token. The EPSS score is not available, and the vulnerability has not been listed in the CISA KEV catalog. The attack vector is a load\u2011time CSRF where the attacker delivers a harbored payload to an authenticated user, causing the user\u2019s browser to submit a forged request with a colliding token. The deterministic nature of the hashing function is the key exploitable condition."}}}}, "created": "2026-04-17T14:45:20.908780+00:00", "updated": "2026-04-18T09:30:25.679472+00:00", "vendors": ["pac4j", "pac4j$PRODUCT$pac4j"]}