{"id":"CVE-2026-117612","kind":"vulnerability","aliases":["CVE-2026-117612"],"related":[],"title":"Jenkins: deserialization filter skipped for classes named in resolves-to","description":"Jenkins 2.587 and earlier, LTS 2.580.1 and earlier does not apply its deserialization filter to classes referenced by the `resolves-to` attribute during XStream deserialization.","summary":"Jenkins does not apply its XStream deserialization filter to classes referenced by the resolves-to attribute, so the filter that normally blocks dangerous classes is bypassed for them. The sources do not say what an attacker gets beyond the deserialization bypass, so code execution is not confirmed.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["ci-cd","jenkins","runtime","self-hosted"],"not_affected_if":["patched-version"],"how_to_check":"- Check the running Jenkins version with `jenkins-cli version` or the footer of the web UI, and compare it against `2.587` (weekly) and `2.580.1` (LTS).\n- unknown","fix":"- Upgrade Jenkins weekly to a release later than `2.587`, or LTS to a release later than `2.580.1`.\n- unknown","status":"open","published_at":"2026-10-28T17:18:20+00:00","first_seen_at":"2026-10-28T17:34:09+00:00","triaged_at":"2026-10-28T17:35:01+00:00","updated_at":"2026-10-28T17:35:01+00:00","category":"runtime","confidence":0.5,"triage":{"at":"2026-10-28T17:35:01Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade Jenkins weekly to a release later than `2.587`, or LTS to a release later than `2.580.1`.\n- unknown","reach":"unknown","title":"Jenkins: deserialization filter skipped for classes named in resolves-to","impact":"high","summary":"Jenkins does not apply its XStream deserialization filter to classes referenced by the resolves-to attribute, so the filter that normally blocks dangerous classes is bypassed for them. The sources do not say what an attacker gets beyond the deserialization bypass, so code execution is not confirmed.","category":"runtime","nicknames":[],"who_cares":["jenkins","self-hosted","ci-cd"],"confidence":0.5,"needs_auth":"unknown","worst_case":"Deserialization filter bypassed, possibly allowing attacker-chosen class instantiation","analyst_note":"Find the Jenkins security advisory for this CVE to confirm fixed versions, required permissions and the actual impact of the filter bypass.","how_to_check":"- Check the running Jenkins version with `jenkins-cli version` or the footer of the web UI, and compare it against `2.587` (weekly) and `2.580.1` (LTS).\n- unknown","needs_analyst":true,"not_affected_if":["patched-version"],"who_is_affected":"Teams running Jenkins weekly at 2.587 or earlier, or LTS at 2.580.1 or earlier, are exposed to the filter bypass. Whether an outside attacker can reach the vulnerable XStream path depends on who can send data to the Jenkins controller, which the sources do not describe. Teams on newer releases can skip this.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000633,"input_tokens":3286,"output_tokens":608,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-117612':13A,16A '-2026':12A,15A '2.580.1':78C '2.587':74C 'appli':28B,83C 'attack':61B 'attribut':41B,95C 'beyond':63B 'block':47B 'bypass':51B,66B 'cd':19B 'ci':18B 'ci-cd':17B 'class':6A,34B,49B,88C 'code':68B 'confirm':72B 'cve':11A,14A 'danger':48B 'deseri':2A,31B,65B,85C,98C 'earlier':76C,80C 'execut':69B 'filter':3A,32B,44B,86C 'get':62B 'host':24B 'jenkin':1A,20B,25B,73C 'lts':77C 'name':7A 'normal':46B 'referenc':35B,89C 'resolv':10A,39B,93C 'resolves-to':9A,38B,92C 'runtim':21B 'say':58B 'self':23B 'self-host':22B 'skip':4A 'sourc':55B 'xstream':30B,97C","nicknames":[],"mitigations":[],"who_affected":"Teams running Jenkins weekly at 2.587 or earlier, or LTS at 2.580.1 or earlier, are exposed to the filter bypass. Whether an outside attacker can reach the vulnerable XStream path depends on who can send data to the Jenkins controller, which the sources do not describe. Teams on newer releases can skip this.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-28T17:18:20+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-117612","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117612","severity":null,"published_at":"2026-10-28T17:18:20+00:00","modified_at":"2026-10-28T17:18:20+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"}