---
title: "CVE-2026-54592\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2026-54592?format=md
keywords: index, follow
---

# CVE-2026-54592

Publication date 1 July 2026

Last updated 1 July 2026

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**7.5 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2026-54592?format=md#impact-score)

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## Description

Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a
Ruby gem. In versions prior to 3.17.3, Oj::Doc#each\_child, when invoked
recursively over a deeply nested JSON document, overflows a fixed-size
stack buffer and aborts the process, leading to DoS. In a two-step chain
in ext/oj/fast.c, doc\_each\_child increments doc->where past the
where\_path[MAX\_STACK = 100] array with no bounds check and never restores
it (the doc->where-- is missing), so calling each\_child recursively from
inside the yield block drives doc->where beyond the array. On the next
entry the function copies the path into the 800-byte stack-local buffer
save\_path[MAX\_STACK] using wlen = doc->where - doc->where\_path, so when
the previous recursive call left doc->where past where\_path[100] the wlen
exceeds MAX\_STACK and the memcpy overflows save\_path on the C stack;
because the Oj::Doc parser imposes no JSON nesting-depth limit (relying on
a C-stack pressure check), deeply nested attacker input reaches this path.
This issue has been fixed in version 3.17.3.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| ruby-oj | 26.04 LTS resolute | Needs evaluation |
| 25.10 questing | Ignored end of life, was needs-triage |
| 24.04 LTS noble | Needs evaluation |
| 22.04 LTS jammy | Needs evaluation |
| 20.04 LTS focal | Needs evaluation |
| 18.04 LTS bionic | Needs evaluation |
| 16.04 LTS xenial | Needs evaluation |
| 14.04 LTS trusty | Needs evaluation |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.5 · High

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | None |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | None |
  | Integrity impact | None |
  | Availability impact | High |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.5 · High |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-54592)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-54592)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2026-54592)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2026-54592)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2026-54592>
* <https://github.com/ohler55/oj/security/advisories/GHSA-3m6q-jj5j-38c9>