VulnerabilityPublished 14 May 2026

CVE-2026-45205: Apache Commons Configuration · Uncontrolled Recursion

Affects Apache Commons ConfigurationSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium : upgrade to 2.15.0 when convenient.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 40% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.15.0

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 14 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Apache Commons Configuration and Apache Software Foundation/org.apache.commons:commons-configuration2 and org.apache.commons/commons-configuration2 to 2.15.0.

Affected software

Product	Affected	Fixed in
Apache Software FoundationApache Commons Configuration	Affected >=2.2 <2.15.0	Fixed in 2.15.0
MavenApache Software Foundation/org.apache.commons:commons-configuration2`pkg:maven/Apache Software Foundation/org.apache.commons:commons-configuration2`Other threats	Affected >=2.2 <2.15.0	Fixed in 2.15.0
Mavenorg.apache.commons/commons-configuration2`pkg:maven/org.apache.commons/commons-configuration2`Other threats	Affected <2.15.0	Fixed in 2.15.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Users should upgrade Apache Commons Configuration to version 2.15.0 or later, where this uncontrolled recursion issue is fixed. No other mitigations or temporary workarounds are indicated. Patch status is not explicitly stated in the vendor advisory, but the recommended upgrade version confirms an official fix is available.

Description

An uncontrolled recursion vulnerability exists in Apache Commons Configuration when processing YAML configuration files containing cycles. This can cause a StackOverflowError, leading to a denial of service. The issue affects versions from 2.2 up to but not including 2.15.0. Upgrading to version 2.15.0 resolves the problem.

Impact

The vulnerability causes a denial of service by crashing the application with a StackOverflowError when processing malicious YAML input containing cycles. There is no impact on confidentiality or integrity. The CVSS score is 5.3 (medium severity), reflecting network attack vector, low complexity, no privileges or user interaction required, and impact limited to availability.

Summary

CVE-2026-45205 is a CWE-674 uncontrolled recursion vulnerability in Apache Commons Configuration. When parsing untrusted YAML configuration files with cyclic references, the library may enter infinite recursion, resulting in a StackOverflowError. This affects Apache Commons Configuration versions starting at 2.2 and prior to 2.15.0. The vulnerability does not impact confidentiality or integrity but causes availability loss due to application crashes. The vendor recommends upgrading to version 2.15.0 where the issue is fixed.

CWE-674Uncontrolled Recursion (opens in a new tab)
Class weakness
The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.
Implementation
Ensure that an end condition will be reached under all logic conditions. The end condition may include checking against the depth of recursion and exiting with an error if the recursion goes too deep. The complexity of the end condition contributes to the effectiveness of this action.
Implementation
Increase the stack size.
Attack patterns
Serialized Data with Nested Payloads (opens in a new tab)
Oversized Serialized Data Payloads (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 9 Jun 2026, 10:43 UTC

WeaknessesCWE-674

Technical details

References

Community reviews

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