CVE-2026-120971
Description
A flaw was found in RESTEasy's default exception mapper. When an unhandled exception other than a WebApplicationException is not handled by an application exception mapper, RESTEasy returns the exception's localized message in the HTTP 500 response body. A remote unauthenticated attacker who can trigger such an exception may obtain information contained in that message. The behavior was reproduced with RESTEasy 7.0.2.Final.
Statement
This vulnerability is rated as Moderate severity because an unauthenticated remote attacker can only trigger read-only information disclosure without compromising system integrity or service availability. In Red Hat deployments utilizing RESTEasy, exposing internal runtime messages requires unexpected server-side failures to occur on endpoints lacking custom exception handlers. Exploitation is constrained to revealing diagnostic text contained in specific exception strings rather than arbitrary memory or privileged data, precluding unauthorized modifications or elevated access.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | N/A | 5.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Often this will either reveal sensitive information which may be used to launch another, more focused attack or disclose private information stored in the server. For example, an attempt to exploit a path traversal weakness (CWE-22) might yield the full pathname of the installed application. In turn, this could be used to select the proper number of ".." sequences to navigate to the targeted file. An attack using SQL injection (CWE-89) might not initially succeed, but an error message could reveal the malformed query, which would expose query logic and possibly even passwords or other sensitive information used within the query.
Acknowledgements
Red Hat would like to thank Yu Bao (PayPal Cyber Security Team) for reporting this issue.
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