What is the CVSS score of CVE-2026-33877?

CVE-2026-33877 has a CVSS 3.1 base score of 3.7 (Low). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N. EPSS exploitation probability: 0.0%.

Is there a patch available for CVE-2026-33877?

Yes, a patch is available for CVE-2026-33877. Update the affected software to the latest version immediately.

Apostrophecms CVE-2026-33877

EUVD-2026-23015 LOW

Observable Timing Discrepancy (CWE-208)

2026-04-15 GitHub_M

GHSA-mj7r-x3h3-7rmr

Information Disclosure Node.js Apostrophe Apostrophecms

3.7

CVSS 3.1 · Vendor: GitHub_M

View

Vulnerability Assessment

Weakness

CWE

CWE-208

ASVS 5.0

V6 - Authentication Timing attack prevention

Monitor Track and reassess. Why: LOW severity (CVSS 0.1-3.9).

Patch available 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Jul 26, 2026

User enumeration via a timing side channel in ApostropheCMS versions 4.28.0 and prior allows unauthenticated attackers to identify valid usernames and emails. The password reset endpoint fails to normalize response time when a valid user is found, enabling an attacker to distinguish valid accounts from invalid ones by repeatedly probing the endpoint. This can facilitate credential stuffing and targeted phishing against instances that have explicitly enabled the password reset feature.

Affected VersionsENISA

Apostrophe < 4.29.0

Affected Packages

npm apostrophe fix: 4.29.0

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in npm

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (GitHub_M) PRIMARY 3.7 LOW

AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

Primary rating from Vendor (GitHub_M) · only source for this CVE.

CVSS VectorVendor: GitHub_M

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Lifecycle Timeline

Patch released

Apr 20, 2026 - 17:05 nvd

Patch available

Apr 16, 2026 - 05:29 EUVD

4.29.0

CVE Published

Apr 15, 2026 - 19:11 nvd

LOW 3.7

DescriptionCVE.org

ApostropheCMS is an open-source Node.js content management system. Versions 4.28.0 and prior contain a timing side-channel vulnerability in the password reset endpoint (/api/v1/@apostrophecms/login/reset-request) that allows unauthenticated username and email enumeration. When a user is not found, the handler returns after a fixed 2-second artificial delay, but when a valid user is found, it performs a MongoDB update and SMTP email send with no equivalent delay normalization, producing measurably different response times. The endpoint also accepts both username and email via an $or query, and has no rate limiting as the existing checkLoginAttempts throttle only applies to the login flow. This enables automated enumeration of valid accounts for use in credential stuffing or targeted phishing. Only instances that have explicitly enabled the passwordReset option are affected, as it defaults to false. This issue has been fixed in version 4.29.0.

Threat Intelligence Overview

EPSS Score

0.0%

Top 92% exploitable

Threat Intel

1 source

Data Quality

6 sources

Confidence: High

EUVD

NVD

CVE.org

EPSS

Vulnrichment GHSA

GitHub

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity LOW

CISA KEV No

Public POC No

EPSS 0.0%

Patch available Yes

Active threat No

Deciding rule

LOW severity (CVSS 0.1-3.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation

Poc

System Exposure· derived

Open

Automatable

Human Impact· derived

Low

Technical Impact

Partial

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +18

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.