{"id":"CVE-2026-117621","kind":"vulnerability","aliases":["CVE-2026-117621"],"related":[],"title":"Jenkins: workspace browser link computed on agent enables cross-site scripting","description":"Jenkins 2.587 and earlier, LTS 2.580.1 and earlier computes on the agent the URL of the link shown in the workspace browser for each file and directory, resulting in a cross-site scripting (XSS) vulnerability exploitable by attackers in control of agent processes.","summary":"Jenkins computes the URL for each file and directory link in the workspace browser on the agent rather than on the controller. An attacker who controls an agent process can inject script into those links, which runs in the browser of a user viewing the workspace.","severity":"medium","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["ci-cd","jenkins","package","self-hosted"],"not_affected_if":["default-config"],"how_to_check":"- Check the Jenkins version with `jenkins --version` or the footer of the web UI; affected are 2.587 and earlier and LTS 2.580.1 and earlier.\n- Identify agents that run untrusted builds or are shared across trust boundaries, since only attackers in control of agent processes can exploit this.","fix":"- Upgrade Jenkins weekly line to a release later than `2.587`.\n- Upgrade the LTS line to a release later than `2.580.1`.","status":"open","published_at":"2026-10-28T17:18:21+00:00","first_seen_at":"2026-10-28T17:34:09+00:00","triaged_at":"2026-10-28T17:34:51+00:00","updated_at":"2026-10-28T17:34:51+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-10-28T17:34:51Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade Jenkins weekly line to a release later than `2.587`.\n- Upgrade the LTS line to a release later than `2.580.1`.","reach":"network","title":"Jenkins: workspace browser link computed on agent enables cross-site scripting","impact":"medium","summary":"Jenkins computes the URL for each file and directory link in the workspace browser on the agent rather than on the controller. An attacker who controls an agent process can inject script into those links, which runs in the browser of a user viewing the workspace.","category":"package","nicknames":[],"who_cares":["jenkins","self-hosted","ci-cd"],"confidence":0.6,"needs_auth":"yes","worst_case":"script runs in a user's browser session on the controller","analyst_note":"Fixed release versions and the exact patched version numbers are not in the source; check the Jenkins security advisory for the fixed version and the required trust level for agents.","how_to_check":"- Check the Jenkins version with `jenkins --version` or the footer of the web UI; affected are 2.587 and earlier and LTS 2.580.1 and earlier.\n- Identify agents that run untrusted builds or are shared across trust boundaries, since only attackers in control of agent processes can exploit this.","needs_analyst":true,"not_affected_if":["default-config"],"who_is_affected":"Jenkins controllers running versions at or below 2.587 (weekly) or 2.580.1 (LTS) where users browse agent workspaces. The attacker must control an agent process, so controllers using only trusted agents are at lower risk. Teams that run only fully trusted agents and restrict workspace browsing can deprioritise this.","user_interaction":"yes","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000635,"input_tokens":3316,"output_tokens":606,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-117621':15A,18A '-2026':14A,17A '2.580.1':78C '2.587':74C 'agent':7A,43B,54B,84C,115C 'attack':50B,111C 'browser':3A,40B,66B,94C 'cd':21B 'ci':20B 'ci-cd':19B 'comput':5A,28B,81C 'control':48B,52B,113C 'cross':10A,104C 'cross-sit':9A,103C 'cve':13A,16A 'directori':35B,99C 'earlier':76C,80C 'enabl':8A 'exploit':109C 'file':33B,97C 'host':26B 'inject':57B 'jenkin':1A,22B,27B,73C 'link':4A,36B,61B,89C 'lts':77C 'packag':23B 'process':55B,116C 'rather':44B 'result':100C 'run':63B 'script':12A,58B,106C 'self':25B 'self-host':24B 'shown':90C 'site':11A,105C 'url':30B,86C 'user':69B 'view':70B 'vulner':108C 'workspac':2A,39B,72B,93C 'xss':107C","nicknames":[],"mitigations":[],"who_affected":"Jenkins controllers running versions at or below 2.587 (weekly) or 2.580.1 (LTS) where users browse agent workspaces. The attacker must control an agent process, so controllers using only trusted agents are at lower risk. Teams that run only fully trusted agents and restrict workspace browsing can deprioritise this.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-28T17:18:21+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-117621","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117621","severity":null,"published_at":"2026-10-28T17:18:21+00:00","modified_at":"2026-10-28T17:18:21+00:00","first_seen_at":"2026-10-28T17:34:09+00:00","fetched_at":"2026-10-28T17:34:09+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"}