{"id":"CVE-2026-117535","kind":"vulnerability","aliases":["CVE-2026-117535"],"related":[],"title":"REDAXO: backend media pool page reflects opener_link, enabling cross-site scripting","description":"REDAXO before 5.21.3 contains a reflected cross-site scripting vulnerability in the backend media pool detail page, where the opener_link parameter is rendered without HTML escaping. Unauthenticated attackers can lure logged-in backend users with media permissions into clicking a crafted link. The injected script can then read the CSRF token and perform actions with the victim's permissions, including code execution via template or module edits when the victim is an administrator.","summary":"REDAXO's backend media pool detail page renders the opener_link parameter without HTML escaping, so a crafted link can inject script into the page. A lured logged-in backend user with media permissions can have the script read the CSRF token and act with their rights, including code execution via template or module edits if the user is an administrator.","severity":"medium","cvss":6.1,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["php","redaxo","runtime","self-hosted"],"not_affected_if":["version-5.21.3-or-later"],"how_to_check":"- Check the installed REDAXO version in the backend or `redaxo/src/core/boot.php`; versions below `5.21.3` are affected.","fix":"- Upgrade REDAXO to `5.21.3` or later.\n- Until upgraded, avoid clicking untrusted links to the backend while logged in.","status":"open","published_at":"2026-10-27T11:17:34+00:00","first_seen_at":"2026-10-27T11:31:28+00:00","triaged_at":"2026-10-27T11:31:58+00:00","updated_at":"2026-10-27T11:31:58+00:00","category":"runtime","confidence":0.6,"triage":{"at":"2026-10-27T11:31:58Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade REDAXO to `5.21.3` or later.\n- Until upgraded, avoid clicking untrusted links to the backend while logged in.","reach":"internet","title":"REDAXO: backend media pool page reflects opener_link, enabling cross-site scripting","impact":"high","summary":"REDAXO's backend media pool detail page renders the opener_link parameter without HTML escaping, so a crafted link can inject script into the page. A lured logged-in backend user with media permissions can have the script read the CSRF token and act with their rights, including code execution via template or module edits if the user is an administrator.","category":"runtime","nicknames":[],"who_cares":["redaxo","php","self-hosted"],"confidence":0.6,"needs_auth":"unknown","worst_case":"Attacker runs script as a logged-in admin and gains code execution.","analyst_note":"","how_to_check":"- Check the installed REDAXO version in the backend or `redaxo/src/core/boot.php`; versions below `5.21.3` are affected.","needs_analyst":false,"not_affected_if":["version-5.21.3-or-later"],"who_is_affected":"Sites running REDAXO before 5.21.3 with a backend that editors and administrators use. The attack needs a logged-in backend user with media permissions to click a crafted link, so sites that do not run the backend in use or are on 5.21.3 or later can skip it.","user_interaction":"yes","needs_special_setup":"no","severity_if_unknown":"medium"},"cost_usd":0.000596,"input_tokens":3368,"output_tokens":519,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-117535':16A,19A '-2026':15A,18A '5.21.3':90C 'act':70B 'action':144C 'administr':87B,163C 'attack':117C 'backend':2A,28B,56B,101C,123C 'click':129C 'code':75B,151C 'contain':91C 'craft':43B,131C 'cross':11A,95C 'cross-sit':10A,94C 'csrf':67B,140C 'cve':14A,17A 'detail':31B,104C 'edit':81B,157C 'enabl':9A 'escap':40B,115C 'execut':76B,152C 'host':25B 'html':39B,114C 'includ':74B,150C 'inject':46B,134C 'link':8A,36B,44B,109C,132C 'log':54B,121C 'logged-in':53B,120C 'lure':52B,119C 'media':3A,29B,59B,102C,126C 'modul':80B,156C 'open':7A,35B,108C 'page':5A,32B,50B,105C 'paramet':37B,110C 'perform':143C 'permiss':60B,127C,149C 'php':20B 'pool':4A,30B,103C 'read':65B,138C 'redaxo':1A,21B,26B,88C 'reflect':6A,93C 'render':33B,112C 'right':73B 'runtim':22B 'script':13A,47B,64B,97C,135C 'self':24B 'self-host':23B 'site':12A,96C 'templat':78B,154C 'token':68B,141C 'unauthent':116C 'user':57B,84B,124C 'via':77B,153C 'victim':147C,160C 'vulner':98C 'without':38B,113C","nicknames":[],"mitigations":[],"who_affected":"Sites running REDAXO before 5.21.3 with a backend that editors and administrators use. The attack needs a logged-in backend user with media permissions to click a crafted link, so sites that do not run the backend in use or are on 5.21.3 or later can skip it.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T11:17:34+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/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":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-117535","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117535","severity":null,"published_at":"2026-10-27T11:17:34+00:00","modified_at":"2026-10-27T11:17:34+00:00","first_seen_at":"2026-10-27T11:31:28+00:00","fetched_at":"2026-10-27T11:31:28+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"}