{"id":"CVE-2026-84918","kind":"vulnerability","aliases":["CVE-2026-84918"],"related":[],"title":"Drupal Monobank payment API: signature verification flaw allows spoofed signatures","description":"Improper Verification of Cryptographic Signature vulnerability in Drupal Monobank payment API allows Signature Spoof. This issue affects Monobank payment API versions: from 0.0.0 to 1.0.3.","summary":"The Drupal Monobank payment API module does not properly verify cryptographic signatures on payment messages. An attacker can forge a signature that the module accepts.","severity":"low","cvss":3.7,"epss":0.00126,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["drupal","monobank","package","payments"],"not_affected_if":["module-not-installed"],"how_to_check":"- Check the installed Monobank payment API module version in the Drupal project (for example with `composer show` or the Drupal extensions page) and see whether it is `1.0.3` or earlier.","fix":null,"status":"open","published_at":"2026-10-22T02:17:02+00:00","first_seen_at":"2026-10-23T21:57:30+00:00","triaged_at":"2026-10-25T04:43:27+00:00","updated_at":"2026-10-25T04:43:27+00:00","category":"package","confidence":0.5,"triage":{"at":"2026-10-25T04:43:27Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"unknown","title":"Drupal Monobank payment API: signature verification flaw allows spoofed signatures","impact":"medium","summary":"The Drupal Monobank payment API module does not properly verify cryptographic signatures on payment messages. An attacker can forge a signature that the module accepts.","category":"package","nicknames":[],"who_cares":["drupal","monobank","payments"],"confidence":0.5,"needs_auth":"unknown","worst_case":"forged payment callbacks accepted as genuine by the site","analyst_note":"Check the Drupal security advisory for the Monobank payment API module for a fixed version and the exact callback path affected.","how_to_check":"- Check the installed Monobank payment API module version in the Drupal project (for example with `composer show` or the Drupal extensions page) and see whether it is `1.0.3` or earlier.","needs_analyst":true,"not_affected_if":["module-not-installed"],"who_is_affected":"Sites running the Drupal Monobank payment API module at version `1.0.3` or earlier that rely on its signature checks for payment callbacks. Sites that do not use this module can skip it. The sources do not say whether a patched version exists.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"low"},"cost_usd":0.000558,"input_tokens":3335,"output_tokens":450,"severity_before":"low"},"analyst_status":null,"analyst_note":null,"search":"'-2026':12A,15A '-84918':13A,16A '0.0.0':68C '1.0.3':70C 'accept':45B 'affect':62C 'allow':8A,57C 'api':4A,25B,56C,65C 'attack':37B 'cryptograph':31B,49C 'cve':11A,14A 'drupal':1A,17B,22B,53C 'flaw':7A 'forg':39B 'improp':46C 'issu':61C 'messag':35B 'modul':26B,44B 'monobank':2A,18B,23B,54C,63C 'packag':19B 'payment':3A,20B,24B,34B,55C,64C 'proper':29B 'signatur':5A,10A,32B,41B,50C,58C 'spoof':9A,59C 'verif':6A,47C 'verifi':30B 'version':66C 'vulner':51C","nicknames":[],"mitigations":[],"who_affected":"Sites running the Drupal Monobank payment API module at version `1.0.3` or earlier that rely on its signature checks for payment callbacks. Sites that do not use this module can skip it. The sources do not say whether a patched version exists.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-22T02:17:02+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","cvss_by":"134c704f-9b21-4f2e-91b3-4a467353bcc0","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-84918","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-84918","severity":null,"published_at":"2026-10-22T02:17:02+00:00","modified_at":"2026-10-22T18:17:30+00:00","first_seen_at":"2026-10-23T21:57:30+00:00","fetched_at":"2026-10-23T22:29:02+00:00","note":null},{"source":"epss","external_id":"CVE-2026-84918","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-84918","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-24T07:15:52+00:00","fetched_at":"2026-10-24T07:15:52+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"}