CVE Intelligence
High Authentication

CVE-2025-42615 — Improper Restriction of Excessive Authentication Attempts vulnerability in CIRCL Vulnerability-Lookup

In affected versions, vulnerability-lookup did not track or limit failed One-Time Password (OTP) attempts during Two-Factor Authentication (2FA) verification. An attacker who already knew or guessed a valid username and password could submit an arbitrary number of OTP codes without causing the account to be locked or generating any specific alert for administrators. This lack of rate-limiting and lockout on OTP failures significantly lowers the cost of online brute-force attacks against 2FA codes and increases the risk of successful account takeover, especially if OTP entropy is reduced (e.g. short numeric codes, user reuse, or predictable tokens). Additionally, administrators had no direct visibility into accounts experiencing repeated 2FA failures, making targeted attacks harder to detect and investigate. The patch introduces a persistent failed_otp_attempts counter on user accounts, locks the user after 5 invalid OTP submissions, resets the counter on successful verification, and surfaces failed 2FA attempts in the admin user list. This enforces an account lockout policy for OTP brute-force attempts and improves monitoring capabilities for suspicious 2FA activity.This issue affects Vulnerability-Lookup: before 2.18.0.

Published Dec 8, 2025 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: ENISA

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.4% (30-day exploitation probability)+5
  • Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.41%
ahead of 34% of scored CVEs · Oct 14, 2026
Affects
CIRCL
Vulnerability-Lookup
CVSS base
8.1
High · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (CIRCL Vulnerability-Lookup).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Exploitation requires user interaction: tighten email/web filtering and warn affected users.
  4. Search available logs for exploit probes matching the vulnerability class (authentication), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
CIRCL Vulnerability-Lookup < 2.18.0 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Attack requirements
None
Privileges required
High
User interaction
Active
Scope
X
Confidentiality (vulnerable system)
High
Integrity (vulnerable system)
None
Availability (vulnerable system)
None
Confidentiality (subsequent)
High
Integrity (subsequent)
None
Availability (subsequent)
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
8.1 CVSS 4.0 High — — a6d3dc9e-0591-4a13-bce7-0f5b31ff6158 via NIST National Vulnerability Database
8.1 CVSS 4.0 High — — ENISA via CVE Program (cve.org) e CISA ADP
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/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 (score shown at the top: a6d3dc9e-0591-4a13-bce7-0f5b31ff6158)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-307 · Improper Restriction of Excessive Authentication Attempts

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.41%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.
web/proxy/WAF logsnetwork IDS/IPSauthentication logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · circl/vulnerability-lookup
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • CVSS changed · 8.1
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Deferred
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • 2025
  • CVE published
    Dec 8, 2025 · ENISA

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

1 on the record

Elsewhere on this site

CIRCL
every CVE for this vendor
Authentication
same class
CWE-307
other pages naming this weakness

Related CVEs (same products)

  • CVE-2025-42616 CSRF vulnerability in CIRCL Vulnerability-Lookup Dec 8, 2025
  • CVE-2025-42620 CSRF vulnerability in CIRCL Vulnerability-Lookup Dec 8, 2025
  • CVE-2025-60249 Cross-site Scripting (XSS) in CIRCL Vulnerability-Lookup Sep 25, 2025

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2025-42615 is "Improper Restriction of Excessive Authentication Attempts vulnerability in CIRCL Vulnerability-Lookup", rated High. It affects Vulnerability-Lookup (CIRCL); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.1 describes technical severity. EPSS 0.41% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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