How severe is CVE-2011-4320?

No CVSS score has been assigned to CVE-2011-4320 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2011-4320?

CVE-2011-4320 affects the following packages: ejabberd (Hex), ejabberd (Hex). Ecosystems affected: Hex.

How do I fix CVE-2011-4320?

Update ejabberd to 2.1.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2011-4320 is resolved across your whole dependency graph.

How do I detect CVE-2011-4320 in my Hex dependencies?

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

How do I mitigate CVE-2011-4320 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2011-4320 actively exploited in the wild?

No public exploit code has been indexed for CVE-2011-4320 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-2011-4320?

CVE-2011-4320 has an EPSS (Exploit Prediction Scoring System) score of 2.0%, placing it in the 81th 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-2011-4320?

CVE-2011-4320 is classified as CWE-399 (CWE-399). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2011-4320 published, and has it been updated?

CVE-2011-4320 was published on February 18, 2012 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💧 Hex

Not in CISA KEV

CVE-2011-4320 — ejabberd

Fix: processone/ejabberd@d3c4eab

CVE-2011-4320 is a CWE-399 vulnerability in ejabberd. A fix is available for ejabberd — see the affected versions and patch details below.

Ejabberd DoS via malformed stanza

Also known asGHSA-2h3q-v47h-f4rc

Published

Feb 18, 2012

Updated

Apr 10, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

2.0%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs81th percentile — riskier than 81% of all scored CVEsHighest risk

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

Real-World Exposure

2 pkgs affected

💧ejabberd💧ejabberd

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

Description

The mod_pubsub module (mod_pubsub.erl) in ejabberd 2.1.8 and 3.0.0-alpha-3 allows remote authenticated users to cause a denial of service (infinite loop) via a stanza with a publish tag that lacks a node attribute.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
💧Hex	`ejabberd`	all versions	2.1.9`mix deps.update ejabberd`
💧Hex	`ejabberd`	≥ 3.0.0-alpha-1&&< 3.0.0-alpha-4	3.0.0-alpha-4`mix deps.update ejabberd`

Affected Products

1 product · 2 configurations

Application

ejabberdprocess-one

2 versions

2.1.83.0.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ejabberd, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ejabberd to 2.1.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2011-4320 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

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