How severe is CVE-2021-40525?

CVE-2021-40525 has a CVSS score of 9.1/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-40525?

CVE-2021-40525 affects the following packages: org.apache.james:james-server (Maven). Ecosystems affected: Maven.

How do I fix CVE-2021-40525?

Update org.apache.james:james-server to 3.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-40525 is resolved across your whole dependency graph.

How do I detect CVE-2021-40525 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.james:james-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-40525 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2021-40525 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-40525 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-40525?

CVE-2021-40525 has an EPSS (Exploit Prediction Scoring System) score of 3.8%, placing it in the 90th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-40525?

CVE-2021-40525 is classified as Path Traversal (CWE-22). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2021-40525 published, and has it been updated?

CVE-2021-40525 was published on January 4, 2022 and was last updated on October 24, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

CRITICAL severity

CVE-2021-40525 — james-server

CRITICAL

CVE-2021-40525 is a critical-severity (CVSS 9.1) Path Traversal vulnerability in org.apache.james:james-server. A fix is available for org.apache.james:james-server — see the affected versions and patch details below.

Path traversal in Apache James

Also known asGHSA-c38m-7h53-g9v4

Published

Jan 4, 2022

Updated

Oct 24, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

3.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs90th percentile — riskier than 90% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

☕org.apache.james:james-server

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Apache James ManagedSieve implementation alongside with the file storage for sieve scripts is vulnerable to path traversal, allowing reading and writing any file. This vulnerability had been patched in Apache James 3.6.1 and higher. We recommend the upgrade. Distributed and Cassandra based products are also not impacted.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.james:james-server`	all versions	3.6.1`org.apache.james:james-server:3.6.1`

Affected Products

1 product · 1 configurations

Application

jamesapache

< 3.6.2

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.james:james-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.james:james-server to 3.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-40525 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2021-40525 in your dependencies?

Find it across Maven, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

9.1/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CWE Classification

CWE-22Path Traversal

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

OpenSSF Scorecard

Package health score

james-project

5.7/10

Code-Review9/10

Maintained10/10

Branch-Protection3/10

Assessed Oct 26, 2026

Timeline

Disclosed

Jan 4, 2022

Last updated

Oct 24, 2026

Identifiers

CVE-2021-40525

GHSA-c38m-7h53-g9v4

References

Advisoryopenwall.com Advisoryopenwall.com Advisoryopenwall.com Advisorynvd.nist.gov · CVE 2021 40525 Packagegithub.com · james project

Related vulnerabilities

This CVE is critical severity; 1 of 8 other CVEs affecting james-server is rated as high or higher (top: critical).

CVE-2023-51747CVE-2023-51518CVE-2022-45935CVE-2022-28220CVE-2015-7611CVE-2004-2650CVE-2022-22931CVE-2021-38542

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 24, 2026

CVE-2021-40525 — james-server

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2021-40525 in your dependencies?