How severe is CVE-2018-1285?

CVE-2018-1285 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2018-1285?

CVE-2018-1285 affects the following packages: log4net (NuGet). Ecosystems affected: NuGet.

How do I fix CVE-2018-1285?

Update log4net to 2.0.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-1285 is resolved across your whole dependency graph.

How do I detect CVE-2018-1285 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for log4net, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2018-1285 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2018-1285 actively exploited in the wild?

No public exploit code has been indexed for CVE-2018-1285 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-2018-1285?

CVE-2018-1285 has an EPSS (Exploit Prediction Scoring System) score of 17.8%, placing it in the 97th 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 warrants monitoring and prompt remediation.

What type of vulnerability is CVE-2018-1285?

CVE-2018-1285 is classified as XML External Entity (XXE) (CWE-611). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2018-1285 published, and has it been updated?

CVE-2018-1285 was published on May 11, 2020 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.

.NET

.NET NuGet

Not in CISA KEV

CRITICAL severity

CVE-2018-1285 — log4net

CRITICAL

CVE-2018-1285 is a critical-severity (CVSS 9.8) XML External Entity (XXE) vulnerability in log4net. EPSS puts its 30-day exploitation probability at 17.8% (97th percentile). A fix is available for log4net — see the affected versions and patch details below.

XML External Entity attack in log4net

Also known asGHSA-2cwj-8chv-9pp9

Published

May 11, 2020

Updated

Oct 24, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

17.8%probability of exploitation in next 30 days

Moderate Risk0.00%

Lower risk than most CVEs97th percentile — riskier than 97% 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

.NETlog4net

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

Description

Apache log4net versions before 2.0.10 do not disable XML external entities when parsing log4net configuration files. This allows for XXE-based attacks in applications that accept attacker-controlled log4net configuration files.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`log4net`	all versions	2.0.10`dotnet add package log4net --version 2.0.10`

Affected Products

7 products · 11 configurations

Application

log4netapache

< 2.0.10

range

fedorafedoraproject

3 versions

303132

Application

manageability software development kitnetapp

all

Application

snapcenternetapp

all

Application

application testing suiteoracle

1 version

13.3.0.1

Application

hospitality opera 5oracle

2 versions

5.55.6

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for log4net, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update log4net to 2.0.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-1285 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

Apache log4net before 2.0.10 does not disable XML external entities when parsing log4net configuration files. This could allow for XXE-based attacks in applications that accept arbitrary configuration files from users.

O3 Security · Impact-Aware SCA

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CVE-2018-1285 — log4net

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-2018-1285 in your dependencies?