CVE-2026-82617
Description
A flaw was found in Apache OpenNLP. The built-in regular expression patterns used for identifying email and URL strings contain inefficient nested repetitions. A remote attacker can exploit this flaw by submitting crafted text to an affected application, triggering excessive CPU consumption or thread stack exhaustion. This issue can cause application unresponsiveness or thread termination, resulting in a Denial of Service (DoS).
Statement
Red Hat has evaluated this vulnerability as having an Important severity rating because an unauthenticated remote attacker can trigger excessive resource exhaustion or thread termination without privileges, directly impacting service availability. Although upstream metrics assess severe system-wide impacts, the vulnerability only leads to denial of service through catastrophic backtracking or thread stack overflow, with no possibility of remote code execution or data leakage. Exploitation is limited to deployments where applications explicitly invoke the default regular expression finders for email addresses and URLs on untrusted, user-supplied content.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
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 | 7.5 | 9.8 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | High | N/A |
| Integrity Impact | None | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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