{"id":"CVE-2026-110018","kind":"vulnerability","aliases":["CVE-2026-110018"],"related":[],"title":"aBlocks WordPress plugin: Contributor can escalate to Editor role","description":"The aBlocks – Gutenberg Blocks, User Dashboard Builder, Popup Builder, Form Builder & Animation Builder plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 2.17.0 via the `/ablocks/v1/form-builder/registration` REST endpoint. The vulnerability exists because the endpoint is registered with `permission_callback => __return_true` and the `register()` handler reads `roleSlug` directly from attacker-controlled block attributes in `post_content` without ever verifying that the block's `formType` is `registration` — a condition that `RegistrationFormSanitizer::verify()` imposes only at save-time, meaning a Contributor can preserve an arbitrary `roleSlug` by saving a block with `formType='login'` and then triggering the endpoint via a valid `wp_rest` nonce and post-ownership check. This makes it possible for authenticated attackers, with Contributor-level access and above, to escalate their WordPress role to Editor or any other non-administrator role and receive a fully authenticated session at the elevated privilege level via `WP_User::set_role()` and `wp_set_auth_cookie()`. Escalation is bounded below administrator-tier roles because `is_safe_registration_role()` rejects any role holding `manage_options`, `edit_users`, `delete_users`, `create_users`, `promote_users`, or `edit_theme_options`, meaning the highest practically reachable role on a standard WordPress installation is Editor.","summary":"The aBlocks WordPress plugin up to and including 2.17.0 exposes a REST registration endpoint whose handler trusts a roleSlug stored in post block attributes, without checking the form type at request time. A logged-in Contributor can save a crafted block, trigger the endpoint, and receive a session at a higher role, up to Editor.","severity":"high","cvss":8.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["package","self-hosted","wordpress","wordpress-plugin"],"not_affected_if":["no-contributor-accounts","patched-version","plugin-not-installed"],"how_to_check":"- Check the installed aBlocks plugin version in the WordPress admin Plugins screen, or with `wp plugin get ablocks --field=version` (the package name is unknown from sources, so confirm the slug)\n- Look for the `/ablocks/v1/form-builder/registration` REST route with `curl -s https://example.com/wp-json/ablocks/v1/` and check whether it is listed","fix":"- Update the aBlocks plugin to a version newer than `2.17.0`; the patched version number is unknown from sources\n- Until patched, deactivate the plugin or restrict Contributor accounts, and review user roles for unexpected Editor accounts created after exposure","status":"open","published_at":"2026-10-24T12:16:54+00:00","first_seen_at":"2026-10-24T12:47:58+00:00","triaged_at":"2026-10-25T02:59:57+00:00","updated_at":"2026-10-25T02:59:57+00:00","category":"package","confidence":0.8,"triage":{"at":"2026-10-25T02:59:57Z","model":"claude-haiku-5-5","output":{"fix":"- Update the aBlocks plugin to a version newer than `2.17.0`; the patched version number is unknown from sources\n- Until patched, deactivate the plugin or restrict Contributor accounts, and review user roles for unexpected Editor accounts created after exposure","reach":"internet","title":"aBlocks WordPress plugin: Contributor can escalate to Editor role","impact":"high","summary":"The aBlocks WordPress plugin up to and including 2.17.0 exposes a REST registration endpoint whose handler trusts a roleSlug stored in post block attributes, without checking the form type at request time. A logged-in Contributor can save a crafted block, trigger the endpoint, and receive a session at a higher role, up to Editor.","category":"package","nicknames":[],"who_cares":["wordpress","wordpress-plugin","self-hosted"],"confidence":0.8,"needs_auth":"yes","worst_case":"Contributor escalates own account to Editor with a session","analyst_note":"Confirm the patched aBlocks version and the plugin's WordPress.org slug from the NVD entry or the vendor changelog; sources do not give a fixed version.","how_to_check":"- Check the installed aBlocks plugin version in the WordPress admin Plugins screen, or with `wp plugin get ablocks --field=version` (the package name is unknown from sources, so confirm the slug)\n- Look for the `/ablocks/v1/form-builder/registration` REST route with `curl -s https://example.com/wp-json/ablocks/v1/` and check whether it is listed","needs_analyst":true,"not_affected_if":["plugin-not-installed","no-contributor-accounts","patched-version"],"who_is_affected":"Sites running the aBlocks plugin at version 2.17.0 or earlier where users with Contributor role or higher can create or edit posts. Exposure depends on the attacker already holding a Contributor-level account, so sites that only have administrators and subscribers are less exposed.","user_interaction":"no","needs_special_setup":"no","severity_if_unknown":"high"},"cost_usd":0.000729,"input_tokens":3739,"output_tokens":711,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-110018':12A,15A '-2026':11A,14A '/ablocks/v1/form-builder/registration':111C '2.17.0':32B,108C 'ablock':1A,25B,81C 'access':206C 'administr':221C,249C 'administrator-ti':248C 'anim':91C 'arbitrari':170C 'attack':136C,201C 'attacker-control':135C 'attribut':47B,139C 'auth':242C 'authent':200C,227C 'block':46B,65B,83C,138C,148C,175C 'bound':246C 'builder':86C,88C,90C,92C 'callback':124C 'check':49B,194C 'condit':154C 'content':142C 'contributor':4A,60B,166C,204C 'contributor-level':203C 'control':137C 'cooki':243C 'craft':64B 'creat':267C 'cve':10A,13A 'dashboard':85C 'delet':265C 'direct':133C 'edit':263C,272C 'editor':8A,79B,215C,287C 'elev':231C 'endpoint':37B,68B,113C,119C,183C 'escal':6A,100C,210C,244C 'ever':144C 'exist':116C 'expos':33B 'form':51B,89C 'formtyp':150C,177C 'fulli':226C 'gutenberg':82C 'handler':39B,130C 'higher':75B 'highest':277C 'hold':260C 'host':19B 'impos':158C 'includ':31B,107C 'instal':285C 'level':205C,233C 'log':58B 'logged-in':57B 'login':178C 'make':196C 'manag':261C 'mean':164C,275C 'non':220C 'non-administr':219C 'nonc':189C 'option':262C,274C 'ownership':193C 'packag':16B 'permiss':123C 'plugin':3A,23B,27B,93C 'popup':87C 'possibl':198C 'post':45B,141C,192C 'post-ownership':191C 'practic':278C 'preserv':168C 'privileg':99C,232C 'promot':269C 'reachabl':279C 'read':131C 'receiv':70B,224C 'regist':121C,129C 'registr':36B,152C,255C 'registrationformsanit':156C 'reject':257C 'request':54B 'rest':35B,112C,188C 'return':125C 'role':9A,76B,213C,222C,238C,251C,256C,259C,280C 'roleslug':42B,132C,171C 'safe':254C 'save':62B,162C,173C 'save-tim':161C 'self':18B 'self-host':17B 'session':72B,228C 'set':237C,241C 'standard':283C 'store':43B 'theme':273C 'tier':250C 'time':55B,163C 'trigger':66B,181C 'true':126C 'trust':40B 'type':52B 'user':84C,236C,264C,266C,268C,270C 'valid':186C 'verifi':145C,157C 'version':103C 'via':109C,184C,234C 'vulner':97C,115C 'whose':38B 'without':48B,143C 'wordpress':2A,20B,22B,26B,95C,212C,284C 'wordpress-plugin':21B 'wp':187C,235C,240C","nicknames":[],"mitigations":[],"who_affected":"Sites running the aBlocks plugin at version 2.17.0 or earlier where users with Contributor role or higher can create or edit posts. Exposure depends on the attacker already holding a Contributor-level account, so sites that only have administrators and subscribers are less exposed.","tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-24T12:16:54+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvss_by":"security@wordfence.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-110018","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-110018","severity":null,"published_at":"2026-10-24T12:16:54+00:00","modified_at":"2026-10-24T12:16:54+00:00","first_seen_at":"2026-10-24T12:47:58+00:00","fetched_at":"2026-10-24T12:47:58+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"}