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jsonata: Malicious inputs to "$toMillis" function can cause resource exhaustion

High severity GitHub Reviewed Published May 29, 2026 in jsonata-js/jsonata • Updated Aug 3, 2026

Package

npm jsonata (npm)

Affected versions

>= 2.0.0, < 2.2.0
< 1.8.9

Patched versions

2.2.0
1.8.9

Description

Impact

Before JSONata 2.2.0 and 1.8.9, it is possible to craft non-matching inputs to the $toMillis function that cause superlinear backtracking in the ISO-8601 validation regex. This may lead to denial of service in applications that evaluate user-provided JSONata expressions.

Patches

This issue has been addressed in JSONata version 2.2.0 or later, and 1.8.9 or later on v1, via fixes that include jsonata-js/jsonata#782 and jsonata-js/jsonata#793. Applications that evaluate user-provided expressions should update ASAP to prevent exploitation.

References

https://github.com/jsonata-js/jsonata/releases/tag/v2.2.0
https://github.com/jsonata-js/jsonata/releases/tag/v1.8.9

Credit

Thank you to Doruk Tan Öztürk for disclosing this issue.

References

@andrew-coleman andrew-coleman published to jsonata-js/jsonata May 29, 2026
Published to the GitHub Advisory Database Jul 2, 2026
Reviewed Jul 2, 2026
Published by the National Vulnerability Database Jul 17, 2026
Last updated Aug 3, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(50th percentile)

Weaknesses

Inefficient Regular Expression Complexity

The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles. Learn more on MITRE.

CVE ID

CVE-2026-52746

GHSA ID

GHSA-86vw-mfpg-wwv9

Source code

Credits

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