CVE-2026-33948
Description
A flaw was found in jq, a command-line JSON processor. This vulnerability allows a remote attacker to bypass input validation by crafting malicious JSON input containing embedded null (NUL) bytes. Due to incorrect handling of input buffer lengths, jq truncates the input at the first NUL byte, validating only the benign prefix and silently discarding any malicious data that follows. This can lead to parser differential attacks where downstream systems, relying on jq for validation, may process the full, unvalidated input, potentially leading to unexpected behavior or security compromises.
Statement
This vulnerability in jq allows an attacker to bypass input validation by embedding NUL bytes in JSON input. This is relevant in Red Hat environments where jq is used to validate untrusted JSON before it is processed by other tools, potentially leading to parser differential attacks and unexpected behavior in downstream systems. The jq command line tool is not exposed to the network in default configurations of Red Hat products.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.8 | 5.3 | N/A |
| Attack Vector | Local | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Changed | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | Low | Low | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Understanding the Weakness (CWE)
Confidentiality,Integrity,Availability
Technical Impact: Read Memory; Execute Unauthorized Code or Commands
The case of an omitted null character is the most dangerous of the possible issues. This will almost certainly result in information disclosure, and possibly a buffer overflow condition, which may be exploited to execute arbitrary code.
Confidentiality,Integrity,Availability
Technical Impact: DoS: Crash, Exit, or Restart; Read Memory; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
If a null character is omitted from a string, then most string-copying functions will read data until they locate a null character, even outside of the intended boundaries of the string. This could: cause a crash due to a segmentation fault cause sensitive adjacent memory to be copied and sent to an outsider trigger a buffer overflow when the copy is being written to a fixed-size buffer.
Integrity,Availability
Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart
Misplaced null characters may result in any number of security problems. The biggest issue is a subset of buffer overflow, and write-what-where conditions, where data corruption occurs from the writing of a null character over valid data, or even instructions. A randomly placed null character may put the system into an undefined state, and therefore make it prone to crashing. A misplaced null character may corrupt other data in memory.
Integrity,Confidentiality,Availability,Access Control,Other
Technical Impact: Alter Execution Logic; Execute Unauthorized Code or Commands
Should the null character corrupt the process flow, or affect a flag controlling access, it may lead to logical errors which allow for the execution of arbitrary code.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
