VulnerabilityPublished 3 Nov 2026

CVE-2026-120971: RESTEasy's default exception mapper · CWE-209

Source GCVE Database

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Authoritative record:CVE-2026-120971· Medium 5.3

Not known to be exploited · CVSS 5.3 Medium.

Data as of 3 Nov 2026, 07:29 UTC

CVSS 3.1 base score

5.3Medium

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (redhat)	CVSS 3.1	5.3

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

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

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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 3 Nov 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 2 Nov 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.

ghsa-q934-x6mh-3877

What to do

Affected software

Product	Affected	Fixed in
Red Hat build of Apache Camel 4 for Quarkus 3resteasy-core	Affected–	Fixed in–
Red Hat build of Apicurio Registry 3resteasy-core	Affected–	Fixed in–
Red Hat build of Debezium 3resteasy-core	Affected–	Fixed in–
Red Hat Build of Keycloakresteasy-core	Affected–	Fixed in–
Red Hat build of Quarkusresteasy-core	Affected–	Fixed in–
Red Hat Fuse 7resteasy-core	Affected–	Fixed in–

AI-suggested

Until a fix is available, applications should implement custom exception mappers to handle exceptions securely and avoid leaking sensitive information in error responses.

Description

A vulnerability in RESTEasy's default exception mapper causes it to return the localized message of unhandled exceptions (other than WebApplicationException) in HTTP 500 responses. This can leak potentially sensitive information to remote unauthenticated attackers who can trigger such exceptions. The issue was confirmed in RESTEasy version 7.0.2.Final.

CWE-209Generation of Error Message Containing Sensitive Information (opens in a new tab)
Base weaknessLikelihood of exploit: HighOWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
The product generates an error message that includes sensitive information about its environment, users, or associated data.
Implementation
Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended).
Implementation
Handle exceptions internally and do not display errors containing potentially sensitive information to a user.
Implementation · Attack Surface Reduction
Use naming conventions and strong types to make it easier to spot when sensitive data is being used. When creating structures, objects, or other complex entities, separate the sensitive and non-sensitive data as much as possible.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Fuzzing for application mapping (opens in a new tab)
Padding Oracle Crypto Attack (opens in a new tab)
Query System for Information (opens in a new tab)
Blind SQL Injection (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 3 Nov 2026, 07:29 UTC

WeaknessesCWE-209

Technical details

References

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