{"id":"CVE-2026-13764","kind":"vulnerability","aliases":["CVE-2026-13764"],"related":[],"title":"WordPress Masterstudy theme: subscribers can escalate to administrator","description":"The Masterstudy - Education WordPress Theme theme for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 4.8.151. This is due to missing authorization and nonce validation on the `masterstudy_ms_stm_set_discard_transient` AJAX action. This makes it possible for authenticated attackers, with Subscriber-level access and above, to elevate their privileges to Administrator by setting the `stm_developer_access_token` transient and using the developer access auto-login flow to obtain administrator session cookies.","summary":"The Masterstudy Education WordPress theme, through version 4.8.151, lacks authorization and nonce checks on an AJAX action. A logged-in subscriber can set a developer access token and use an auto-login flow to obtain an administrator session.","severity":"high","cvss":8.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["masterstudy-theme","package","self-hosted","wordpress"],"not_affected_if":["no-public-registration","theme-not-installed"],"how_to_check":"- Check the installed Masterstudy theme version in Appearance > Themes or the style.css header.\n- Look for the `masterstudy_ms_stm_set_discard_transient` action in the theme's PHP files.","fix":"- Update the Masterstudy theme to a version newer than `4.8.151`; the fixed version is unknown from the sources.","status":"open","published_at":"2026-11-12T12:18:23+00:00","first_seen_at":"2026-11-12T12:38:18+00:00","triaged_at":"2026-11-12T12:40:33+00:00","updated_at":"2026-11-12T12:40:33+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-11-12T12:40:33Z","model":"claude-haiku-5-5","output":{"fix":"- Update the Masterstudy theme to a version newer than `4.8.151`; the fixed version is unknown from the sources.","reach":"internet","title":"WordPress Masterstudy theme: subscribers can escalate to administrator","impact":"high","summary":"The Masterstudy Education WordPress theme, through version 4.8.151, lacks authorization and nonce checks on an AJAX action. A logged-in subscriber can set a developer access token and use an auto-login flow to obtain an administrator session.","audience":"businesses","category":"package","nicknames":[],"who_cares":["wordpress","masterstudy-theme","self-hosted"],"confidence":0.7,"fix_status":"unknown","needs_auth":"yes","worst_case":"Subscriber becomes administrator, gaining full control of the WordPress site","analyst_note":"Confirm the fixed Masterstudy theme version and whether the developer access auto-login feature must be enabled, using the NVD entry and the vendor changelog.","how_to_check":"- Check the installed Masterstudy theme version in Appearance > Themes or the style.css header.\n- Look for the `masterstudy_ms_stm_set_discard_transient` action in the theme's PHP files.","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["theme-not-installed","no-public-registration"],"who_is_affected":"Sites running the Masterstudy Education WordPress theme at version 4.8.151 or older where users can register or hold a subscriber account. Sites without this theme, or where only trusted administrators have accounts, are not exposed by this flaw. The sources do not say whether the developer access feature must be enabled.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000774,"input_tokens":4638,"output_tokens":621,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-13764':11A,14A '-2026':10A,13A '4.8.151':30B,83C 'access':49B,114C,128C,135C 'action':39B,102C 'administr':8A,61B,122C,142C 'ajax':38B,101C 'attack':109C 'authent':108C 'author':32B,89C 'auto':55B,137C 'auto-login':54B,136C 'check':35B 'cooki':144C 'cve':9A,12A 'develop':48B,127C,134C 'discard':99C 'due':86C 'educ':25B,65C 'elev':118C 'escal':6A,75C 'flow':57B,139C 'host':21B 'includ':82C 'lack':31B 'level':113C 'log':42B 'logged-in':41B 'login':56B,138C 'make':104C 'masterstudi':2A,16B,24B,64C,95C 'masterstudy-them':15B 'miss':88C 'ms':96C 'nonc':34B,91C 'obtain':59B,141C 'packag':18B 'possibl':106C 'privileg':74C,120C 'self':20B 'self-host':19B 'session':62B,143C 'set':46B,98C,124C 'stm':97C,126C 'subscrib':4A,44B,112C 'subscriber-level':111C 'theme':3A,17B,27B,67C,68C 'token':50B,129C 'transient':100C,130C 'use':52B,132C 'valid':92C 'version':29B,78C 'vulner':72C 'wordpress':1A,22B,26B,66C,70C","nicknames":[],"mitigations":[],"who_affected":"Sites running the Masterstudy Education WordPress theme at version 4.8.151 or older where users can register or hold a subscriber account. Sites without this theme, or where only trusted administrators have accounts, are not exposed by this flaw. The sources do not say whether the developer access feature must be enabled.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"unknown","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["high","masterstudytheme","package","selfhosted","wordpress"],"campaign_type":null,"search_a":"'-13764':11A,14A '-2026':10A,13A 'administr':8A 'cve':9A,12A 'escal':6A 'masterstudi':2A 'subscrib':4A 'theme':3A 'wordpress':1A","search_b":"'4.8.151':30B 'access':49B 'action':39B 'administr':61B 'ajax':38B 'author':32B 'auto':55B 'auto-login':54B 'check':35B 'develop':48B 'educ':25B 'flow':57B 'host':21B 'lack':31B 'log':42B 'logged-in':41B 'login':56B 'masterstudi':16B,24B 'masterstudy-them':15B 'nonc':34B 'obtain':59B 'packag':18B 'self':20B 'self-host':19B 'session':62B 'set':46B 'subscrib':44B 'theme':17B,27B 'token':50B 'use':52B 'version':29B 'wordpress':22B,26B","search_c":"'4.8.151':83C 'access':114C,128C,135C 'action':102C 'administr':122C,142C 'ajax':101C 'attack':109C 'authent':108C 'author':89C 'auto':137C 'auto-login':136C 'cooki':144C 'develop':127C,134C 'discard':99C 'due':86C 'educ':65C 'elev':118C 'escal':75C 'flow':139C 'includ':82C 'level':113C 'login':138C 'make':104C 'masterstudi':64C,95C 'miss':88C 'ms':96C 'nonc':91C 'obtain':141C 'possibl':106C 'privileg':74C,120C 'session':143C 'set':98C,124C 'stm':97C,126C 'subscrib':112C 'subscriber-level':111C 'theme':67C,68C 'token':129C 'transient':100C,130C 'use':132C 'valid':92C 'version':78C 'vulner':72C 'wordpress':66C,70C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-12T12:18:23+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-2026-13764","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-13764","severity":null,"published_at":"2026-11-12T12:18:23+00:00","modified_at":"2026-11-12T12:18:23+00:00","first_seen_at":"2026-11-12T12:38:18+00:00","fetched_at":"2026-11-12T12:38:18+00:00","note":null}],"documents":[],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}