{"id":"CVE-2026-105861","kind":"vulnerability","aliases":["CVE-2026-105861","GHSA-pj5h-5q6c-3pfx"],"related":[],"title":"Payload external upload trust validation issue","description":"## Impact\n\nUnder certain external upload configurations, Payload could send authentication data to a destination that was not verified as trusted. If the affected request contained a valid session, this could expose that session to an unintended recipient.\n\n**You are affected if:**\n\n- You have enabled external URL-based upload retrieval, where authenticated requests can trigger it.\n\n## Patches\n\nPayload now validates the destination before forwarding authentication data and reapplies that validation when a request changes destination.\n\nUsers should upgrade Payload packages to `>= 3.90.0` or `>= 4.0.0-canary.34`.\n\n## Workarounds\nIt is recommended to update all Payload packages to `>= 3.90.0` or `>= 4.0.0-canary.34`.\n\nIf you cannot, a valid workaround exists:\n- Disable external URL-based upload retrieval where practical.\n- If you cannot disable it, configure the upload header filter to remove authentication data from outbound file requests.\n- Restrict access to the affected upload functionality.","summary":"Payload CMS sends authentication data to unverified destinations when external URL-based upload retrieval is enabled. An attacker who can get an authenticated request to trigger an upload fetch can receive the victim's valid session.","severity":"high","cvss":8.2,"epss":0.0013500000350177288,"exploited":false,"exploited_at":null,"products":[{"name":"payload","fixed":["3.90.0"],"affected":">= 3.0.0, < 3.90.0","ecosystem":"npm"},{"name":"payload","fixed":["4.0.0-canary.34"],"affected":">= 4.0.0-canary.0, < 4.0.0-canary.34","ecosystem":"npm"},{"name":"payloadcms payload","fixed":["3.90.0"],"affected":">= 3.0.0, < 3.90.0","ecosystem":"vendor"},{"name":"payloadcms payload","fixed":[],"affected":"= 4.0.0","ecosystem":"vendor"}],"ecosystems":["npm","vendor"],"tags":["cms","cwe-200","cwe-346","node","package","payload","self-hosted"],"not_affected_if":["default-config","no-external-upload-urls"],"how_to_check":"Check whether upload external URL retrieval is enabled in the Payload upload config (fetch from external URLs).\nRun: npm ls payload to see the installed version; affected if 3.x < 3.90.0 or 4.0.0-canary.x < 4.0.0-canary.34.","fix":"Upgrade payload packages to >= 3.90.0 or >= 4.0.0-canary.34.\nIf you cannot upgrade, disable external URL-based upload retrieval or configure the upload header filter to strip auth headers from outbound file requests.","status":"open","published_at":"2026-10-06T17:17:22+00:00","first_seen_at":"2026-10-23T19:11:32+00:00","triaged_at":"2026-10-23T20:20:09+00:00","updated_at":"2026-10-23T23:44:52+00:00","category":"package","confidence":0.8,"triage":{"at":"2026-10-23T20:20:09Z","model":"claude-haiku-5-5","output":{"fix":"Upgrade payload packages to >= 3.90.0 or >= 4.0.0-canary.34.\nIf you cannot upgrade, disable external URL-based upload retrieval or configure the upload header filter to strip auth headers from outbound file requests.","summary":"Payload CMS sends authentication data to unverified destinations when external URL-based upload retrieval is enabled. An attacker who can get an authenticated request to trigger an upload fetch can receive the victim's valid session.","category":"package","who_cares":["payload","node","self-hosted","cms"],"confidence":0.8,"analyst_note":"","how_to_check":"Check whether upload external URL retrieval is enabled in the Payload upload config (fetch from external URLs).\nRun: npm ls payload to see the installed version; affected if 3.x < 3.90.0 or 4.0.0-canary.x < 4.0.0-canary.34.","needs_analyst":false,"not_affected_if":["default-config","no-external-upload-urls"],"severity_if_unknown":"high"},"cost_usd":0.000412,"input_tokens":2328,"output_tokens":359,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-105861':9A,17A '-200':26B '-2026':8A,16A '-346':28B '3.90.0':153C,167C '3pfx':14A '4.0.0':155C,169C '5q6c':13A 'access':206C 'affect':94C,111C,209C 'attack':53B 'authent':38B,58B,81C,123C,136C,199C 'base':47B,119C,182C 'canary.34':156C,170C 'cannot':173C,189C 'certain':74C 'chang':145C 'cms':24B,36B 'configur':77C,192C 'contain':96C 'could':79C,101C 'cve':7A,15A 'cwe':25B,27B 'data':39B,82C,137C,200C 'destin':42B,85C,133C,146C 'disabl':178C,190C 'enabl':51B,115C 'exist':177C 'expos':102C 'extern':2A,44B,75C,116C,179C 'fetch':64B 'file':203C 'filter':196C 'forward':135C 'function':211C 'get':56B 'ghsa':11A 'ghsa-pj5h-5q6c-3pfx':10A 'header':195C 'host':34B 'impact':72C 'issu':6A 'node':29B 'outbound':202C 'packag':30B,151C,165C 'patch':128C 'payload':1A,18A,19A,21A,23A,31B,35B,78C,129C,150C,164C 'payloadcms':20A,22A 'pj5h':12A 'practic':186C 'reappli':139C 'receiv':66B 'recipi':108C 'recommend':160C 'remov':198C 'request':59B,95C,124C,144C,204C 'restrict':205C 'retriev':49B,121C,184C 'self':33B 'self-host':32B 'send':37B,80C 'session':71B,99C,104C 'trigger':61B,126C 'trust':4A,91C 'unintend':107C 'unverifi':41B 'updat':162C 'upgrad':149C 'upload':3A,48B,63B,76C,120C,183C,194C,210C 'url':46B,118C,181C 'url-bas':45B,117C,180C 'user':147C 'valid':5A,70B,98C,131C,141C,175C 'verifi':89C 'victim':68B 'workaround':157C,176C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-06T17:17:22+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/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","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"ghsa","external_id":"GHSA-pj5h-5q6c-3pfx","url":"https://github.com/advisories/GHSA-pj5h-5q6c-3pfx","severity":"high","published_at":"2026-10-07T20:29:41+00:00","modified_at":"2026-10-20T08:00:34+00:00","first_seen_at":"2026-10-23T19:11:32+00:00","fetched_at":"2026-10-23T19:11:32+00:00","note":null},{"source":"nvd","external_id":"CVE-2026-105861","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-105861","severity":null,"published_at":"2026-10-06T17:17:22+00:00","modified_at":"2026-10-15T00:09:43+00:00","first_seen_at":"2026-10-23T23:44:52+00:00","fetched_at":"2026-10-23T23:44:52+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}