CVE-2026-86049
Description
A flaw was found in Jupyter Server. The server's logging mechanism for HTTP 500 errors fails to properly redact sensitive information. When a request results in an HTTP 500 error and includes a Referer header containing a security token, this token is written to server logs in plaintext. An attacker with access to these logs could retrieve the token, potentially gaining unauthorized access to the affected user's Jupyter Server permissions.
Statement
This vulnerability is rated as Moderate impact because exploiting it requires an unhandled HTTP 500 error condition and direct access to the server's logging output. In Red Hat OpenShift AI, notebook workloads execute within managed container environments where log inspection is restricted to authorized cluster administrators and workload owners through platform access controls. Consequently, while authentication tokens present in request headers can be recorded without proper sanitization during server faults, unauthorized third parties cannot capture these credentials remotely without preexisting elevated privileges.
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 | 4.8 | N/A | 7.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | Low | N/A | Low |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | High |
| Availability Impact | None | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability,Non-Repudiation
Technical Impact: Modify Application Data; Hide Activities; Execute Unauthorized Code or Commands
Interpretation of the log files may be hindered or misdirected if an attacker can supply data to the application that is subsequently logged verbatim. In the most benign case, an attacker may be able to insert false entries into the log file by providing the application with input that includes appropriate characters. Forged or otherwise corrupted log files can be used to cover an attacker's tracks, possibly by skewing statistics, or even to implicate another party in the commission of a malicious act. If the log file is processed automatically, the attacker can render the file unusable by corrupting the format of the file or injecting unexpected characters. An attacker may inject code or other commands into the log file and take advantage of a vulnerability in the log processing utility.
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