{"id":"CVE-2026-109140","kind":"vulnerability","aliases":["CVE-2026-109140"],"related":[],"title":"Krill: any logged-in user can forge an admin session token because the encryption nonce resets on restart","description":"The vulnerability is that Krill encrypts every login-session token with a nonce built from a counter that is reset to 0 on every Krill restart, so the same (key, nonce) pair is used again after each restart.","summary":"Krill encrypts each login-session token with a nonce from a counter that resets to 0 on every restart, so the same key and nonce pair is reused. Reused nonces can let an attacker recover session token contents or forge valid tokens.","severity":"high","cvss":8.4,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"krill","fixed":["0.16.1"],"affected":"<= 0.16.0","ecosystem":"vendor"}],"ecosystems":[],"tags":["auth-required","infrastructure","krill","rpki","self-hosted"],"not_affected_if":["not-running-krill"],"how_to_check":"Run `krill --version` (or `krillc --version`). Krill 0.16.0 and earlier is affected; 0.16.1 or later is fixed. Distribution packages may differ, so check the package changelog.","fix":"Install Krill 0.16.1 or later.","status":"open","published_at":"2026-11-02T16:17:26+00:00","first_seen_at":"2026-11-02T16:24:04+00:00","triaged_at":"2026-11-02T16:26:27+00:00","updated_at":"2026-11-02T16:33:09+00:00","category":"infrastructure","confidence":0.85,"triage":{"at":"2026-11-02T16:26:27Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"unknown","title":"Krill: session tokens reuse encryption nonces after every restart","impact":"high","summary":"Krill encrypts each login-session token with a nonce from a counter that resets to 0 on every restart, so the same key and nonce pair is reused. Reused nonces can let an attacker recover session token contents or forge valid tokens.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["krill","rpki","self-hosted"],"confidence":0.6,"fix_status":"unknown","needs_auth":"unknown","worst_case":"attacker may forge or decrypt login session tokens","analyst_note":"Find the fixed Krill version and the NVD or project advisory text on whether the attack needs network access or an existing session; source is https://nvd.nist.gov/vuln/detail/CVE-2026-109140.","how_to_check":"- Check the Krill version in use (`krill --version`) and compare it with the fixed versions in the sources, which the sources do not state.\n- unknown","plain_action":"","needs_analyst":true,"not_affected_if":["not-running-krill"],"who_is_affected":"Operators running Krill, the RPKI certificate authority software, are exposed because its login-session tokens are encrypted with reused nonces after each restart. The sources do not say which deployments or configurations are affected beyond this. Teams not running Krill can skip it.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.00067,"input_tokens":4088,"output_tokens":523,"severity_before":"high"},"analyst_status":"done","analyst_note":"Find the fixed Krill version and the NVD or project advisory text on whether the attack needs network access or an existing session; source is https://nvd.nist.gov/vuln/detail/CVE-2026-109140.","search":"'-109140':22A,25A '-2026':21A,24A '0':52B,101C 'admin':10A 'attack':70B 'auth':28B 'auth-requir':27B 'built':93C 'content':74B 'counter':48B,96C 'cve':20A,23A 'encrypt':15A,37B,84C 'everi':54B,85C,103C 'forg':8A,76B 'host':35B 'infrastructur':30B 'key':59B,109C 'krill':1A,26A,31B,36B,83C,104C 'let':68B 'log':4A 'logged-in':3A 'login':40B,87C 'login-sess':39B,86C 'nonc':16A,45B,61B,66B,92C,110C 'pair':62B,111C 'recov':71B 'requir':29B 'reset':17A,50B,99C 'restart':19A,55B,105C,117C 'reus':64B,65B 'rpki':32B 'self':34B 'self-host':33B 'session':11A,41B,72B,88C 'token':12A,42B,73B,78B,89C 'use':113C 'user':6A 'valid':77B 'vulner':80C","nicknames":[],"mitigations":[],"who_affected":"Anyone running Krill (NLnet Labs' RPKI certificate authority software) up to and including 0.16.0 with login users. The vendor says any user who can log in can forge an admin session token, so the risk is mainly from accounts that are not meant to be admins. Teams not running Krill can skip it.","tier":"B","verified":{"fix":{"at":"2026-11-02T16:33:09Z","by":"analyst","doc":"https://www.nlnetlabs.nl/downloads/krill/CVE-2026-109140.txt","run_id":1403},"products":{"at":"2026-11-02T16:33:09Z","by":"analyst","doc":"https://www.nlnetlabs.nl/downloads/krill/CVE-2026-109140.txt","run_id":1403},"how_to_check":{"at":"2026-11-02T16:33:09Z","by":"analyst","doc":"https://www.nlnetlabs.nl/downloads/krill/CVE-2026-109140.txt","run_id":1403},"who_affected":{"at":"2026-11-02T16:33:09Z","by":"analyst","doc":"https://www.nlnetlabs.nl/downloads/krill/CVE-2026-109140.txt","run_id":1403}},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":["krill"],"ptokens":["krill"],"labels":["authrequired","high","infrastructure","krill","rpki","selfhosted"],"first_public_at":"2026-11-02T16:17:26+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L","cvss_by":"sep@nlnetlabs.nl","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-109140","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-109140","severity":null,"published_at":"2026-11-02T16:17:26+00:00","modified_at":"2026-11-02T16:17:26+00:00","first_seen_at":"2026-11-02T16:24:04+00:00","fetched_at":"2026-11-02T16:24:04+00:00","note":null},{"source":"analyst","external_id":"CVE-2026-109140:1403","url":null,"severity":null,"published_at":"2026-11-02T16:33:09+00:00","modified_at":"2026-11-02T16:33:09+00:00","first_seen_at":"2026-11-02T16:33:09+00:00","fetched_at":"2026-11-02T16:33:09+00:00","note":"Read NLnet Labs advisory (.txt) and CNA record: Krill <= 0.16.0 affected, fixed in 0.16.1. Advisory says any user who can log in can forge an admin token (needs a valid login, not anonymous; CVSS AV:N/AC:H/PR:L). No exploitation or PoC seen. Mitigations: none stated by vendor."}],"documents":[{"id":52879,"url":"https://www.nlnetlabs.nl/downloads/krill/CVE-2026-109140.txt","title":"NLnet Labs advisory CVE-2026-109140 (Krill)","kind":"advisory","source":"analyst","publisher":null,"text":null,"published_at":null,"relation":"advisory","confidence":null,"note":null},{"id":52880,"url":"https://cveawg.mitre.org/api/cve/CVE-2026-109140","title":"CVE record CVE-2026-109140 (CNA NLnet Labs)","kind":"other","source":"analyst","publisher":null,"text":null,"published_at":null,"relation":"describes","confidence":null,"note":null}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}