{"id":"CVE-2025-26399","published":"2025-09-23T05:15:35Z","modified":"2026-10-11T20:10:00Z","title":"SolarWinds Web Help Desk Deserialization of Untrusted Data Vulnerability","vendor":"SolarWinds","product":"Web Help Desk","tier":"core","eol":null,"description":{"text":"SolarWinds Web Help Desk was found to be susceptible to an unauthenticated AjaxProxy deserialization remote code execution vulnerability that, if exploited, would allow an attacker to run commands on the host machine. This vulnerability is a patch bypass of CVE-2024-28988, which in turn is a patch bypass of CVE-2024-28986.","provenance":"source","from":"NVD"},"summary":{"text":"SolarWinds Web Help Desk contains a deserialization of untrusted data flaw in its AjaxProxy component. The product is a web-based IT help desk application from SolarWinds. An unauthenticated attacker with network access to the application can send crafted input to the AjaxProxy component and run commands on the host machine, with no user interaction or prior credentials required.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-29T07:10:53Z"},"cvss":{"score":9.8,"severity":"CRITICAL","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.9012,"percentile":0.99795,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2026-03-09","dueDate":"2026-03-12","ransomware":true,"requiredAction":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","notes":"https://www.solarwinds.com/trust-center/security-advisories/cve-2025-26399 ; https://documentation.solarwinds.com/en/success_center/whd/content/release_notes/whd_12-8-7-hotfix-1_release_notes.htm ; https://nvd.nist.gov/vuln/detail/CVE-2025-26399","provenance":"source"},"vulncheckKev":{"dateAdded":"2026-01-20","exploitedFirstSeen":"2026-01-20","ransomware":true,"evidence":[{"url":"https://www.loginsoft.com/reports/annually/vulnerability-intelligence-report-2025","date":"2026-01-20"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2026-03-09"},{"url":"https://www.recordedfuture.com/blog/march-2026-cve-landscape","date":"2026-04-13"},{"url":"https://www.sophos.com/en-us/blog/qemu-abused-to-evade-detection-and-enable-ransomware-delivery","date":"2026-04-16"},{"url":"https://securelist.com/vulnerabilities-and-exploits-in-q1-2026/119733/","date":"2026-05-07"},{"url":"https://www.resecurity.com/es/blog/article/the-anubis-ransomware-attack-on-the-adriatic-port-authority","date":"2026-06-11"},{"url":"https://cyble.com/reports/H1-2026-Global-Threat-Landscape-Report.pdf","date":"2026-07-27"}],"evidenceTotal":7,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 30, 2026","url":"https://otx.alienvault.com/pulse/6ae35d889ea92b4ce19c2680","created":"2026-10-29"},{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"}],"provenance":"machine"},"cwes":[{"id":"CWE-502","name":"Deserialization of Untrusted Data"}],"references":[{"url":"https://documentation.solarwinds.com/en/success_center/whd/content/release_notes/whd_12-8-7-hotfix-1_release_notes.htm","tags":["Release Notes"]},{"url":"https://www.solarwinds.com/trust-center/security-advisories/CVE-2025-26399","tags":["Patch","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-26399","tags":["US Government Resource"]},{"url":"https://www.microsoft.com/en-us/security/blog/2026/02/06/active-exploitation-solarwinds-web-help-desk/","tags":["Third Party Advisory"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: unauthenticated remote exploit of exposed web app","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"unauthenticated AjaxProxy deserialization remote code execution vulnerability","start":59,"end":136}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1059","name":"Command and Scripting Interpreter","tactics":["execution"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: deserialization RCE enables command execution","mappingType":"primary_impact","evidence":[{"from":"description","quote":"would allow an attacker to run commands on the host machine","start":157,"end":216}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2025-30842","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-30842","exploited":true,"exploitedSince":"2026-03-09","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":1,"skipped":0,"earliest":"2025-09-23","earliestUrl":"https://github.com/rxerium/CVE-2025-26399","repos":[{"name":"rxerium/CVE-2025-26399","url":"https://github.com/rxerium/CVE-2025-26399","stars":2,"created":"2025-09-23"}]},"nuclei":[{"id":"CVE-2025-26399","name":"SolarWinds Web Help Desk < 12.8.7 - AjaxProxy Deserialization RCE","severity":"critical","path":"http/cves/2025/CVE-2025-26399.yaml","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-26399.yaml"}],"first":{"date":"2025-09-23","source":"PoC-in-GitHub","url":"https://github.com/rxerium/CVE-2025-26399"},"provenance":"source"},"detections":{"cveRules":[{"title":"Suspicious Child Process of SolarWinds WebHelpDesk","id":"8c7f4a2d-3b9e-4f1c-9a6d-2e8f5c3d9a1b","level":"high","status":"experimental","path":"rules-emerging-threats/2025/Exploits/CVE-2025-40551/proc_creation_win_exploit_cve_2025_40551.yml","url":"https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2025/Exploits/CVE-2025-40551/proc_creation_win_exploit_cve_2025_40551.yml","techniques":["T1190"]}]},"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"ai"},{"stage":"primary","techniques":["T1059"],"provenance":"ai"}],"timeline":[{"date":"2025-09-23","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-26399","provenance":"source"},{"date":"2025-09-23","kind":"exploit-public","label":"First public exploit: PoC-in-GitHub","url":"https://github.com/rxerium/CVE-2025-26399","provenance":"source"},{"date":"2026-01-20","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://www.loginsoft.com/reports/annually/vulnerability-intelligence-report-2025","provenance":"source"},{"date":"2026-03-09","kind":"kev","label":"Added to CISA KEV (known ransomware use)","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2026-03-09","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-30842","provenance":"source"}],"speed":{"daysToPublicExploit":0,"firstExploitFrom":"PoC-in-GitHub","daysToKev":167},"priority":{"score":84.8,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":5.0,"detail":"added 283 days ago"},{"name":"Known ransomware use","points":10.0,"detail":"CISA KEV and VulnCheck KEV: Known"},{"name":"EPSS percentile","points":19.96,"detail":"percentile 0.9980"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"1 PoC-in-GitHub repo; 1 nuclei template"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":6.86,"detail":"base score 9.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]},"lineage":{"familyId":"fam-solarwinds-web-help-desk-cve-2024-28988","parents":[{"from":"CVE-2024-28988","to":"CVE-2025-26399","relation":"bypass","confidence":"high","kind":"lineage","evidence":[{"kind":"text","provenance":"source","relation":"bypass","quote":"This vulnerability is a patch bypass of CVE-2024-28988, which in turn is a patch bypass of 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