What is the CVSS score of CVE-2025-40931?

CVE-2025-40931 has a CVSS 3.1 base score of 9.1 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. EPSS exploitation probability: 0.0%.

How to fix or mitigate CVE-2025-40931?

Within 24 hours: Inventory all Apache instances and identify vulnerable versions; establish incident response team and enable enhanced logging/monitoring. Within 7 days: Implement compensating controls (WAF rules, network segmentation, disable unnecessary modules); begin testing alternative or hardened Apache configurations. Within 30 days: Prioritize patching immediately upon vendor release; evaluate migration to patched versions or alternative solutions if patch timeline becomes unacceptable.

Apache CVE-2025-40931

CRITICAL

Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) (CWE-338)

2026-03-05 9b29abf9-4ab0-4765-b253-1875cd9b441e

Apache Information Disclosure Chorny

9.1

CVSS 3.1 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-338 OWASP Top 10:2025 A04:2025 - Cryptographic Failures ASVS 5.0 V11 - Cryptography Cryptographic PRNG selection
Impact	CVSS 9.1.
Exploit ScenarioDerived	Predict session IDs.

Act Now Prioritize within 24-48h. Why: CRITICAL severity.

No patch listed yet 0.0% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Mar 12, 2026

Insecure session ID generation in Apache::Session::Generate::MD5 through 1.94 for Perl.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 22:06 CVSS 9.1

Weak MD5 session IDs in Apache::Session.

RemediationAI

Update.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

CWE-338.

Know when Chorny gets its next vulnerability

Watch products and get an email when something new is published
Check this CVE against your own stack and servers
Exploit and PoC references, threat intelligence from 22 sources

Continue with Google Continue with GitHub

No credit card · 7-day full trial

Severity by source

NVD PRIMARY 9.1 CRITICAL

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

SUSE CRITICAL

Primary rating from NVD.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

DescriptionCVE.org

Apache::Session::Generate::MD5 versions through 1.94 for Perl create insecure session id.

Apache::Session::Generate::MD5 generates session ids insecurely. The default session id generator returns a MD5 hash seeded with the built-in rand() function, the epoch time, and the PID. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. Predicable session ids could allow an attacker to gain access to systems.

Executive ViewAI

Why It Matters

A critical vulnerability (CVSS 9.1) affecting Apache has been disclosed with no patch currently available, creating immediate risk for any organization running vulnerable versions. Attackers can exploit this flaw to gain unauthorized system access, potentially compromising sensitive data, applications, and infrastructure across your environment.

Business Impact: Severe

Compensating Controls

Deploy WAF rules to detect/block exploitation attempts; implement strict network segmentation limiting Apache access to trusted sources only; disable non-essential Apache modules and features; apply input validation and rate limiting; increase monitoring and alerting for suspicious connection patterns; consider running Apache in containerized/sandboxed environments; restrict administrative access; evaluate temporary service restrictions or failover to unaffected systems until patch availability.

Threat Intelligence Overview

EPSS Score

0.0%

Top 87% exploitable

Data Quality

5 sources

Confidence: Medium

NVD

CVE.org

EPSS Vendor

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 CRITICAL

CISA KEV No

Public POC No

EPSS 0.0%

Patch available No

Active threat No

Deciding rule

CRITICAL severity

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

Out-of-Cycle

Exploitation· derived

None

System Exposure· derived

Open

Automatable· derived

Yes

Human Impact

Very High

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +46

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.