CVE-2026-32875Public exploitNetwork attack vector

Service crash or hang via indent arithmetic

Published Mar 20, 2026 · Updated Mar 20, 2026

Denial of service in UltraJSON 5.1.0 through 5.11.0 allows remote attackers to crash or hang services via crafted indent values. The encoder multiplies indent by nesting depth using insufficient integer widths, underestimating buffer space or underflowing the buffer-growth target. Exposure requires an application to pass attacker-controlled indentation, or a fixed negative indent, to dump, dumps, or encode on nested data.

CVSS severity7.5
High
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in UltraJSON 5.1.0 through 5.11.0 allows remote attackers to crash or hang services via crafted indent values. The encoder multiplies indent by nesting depth using insufficient integer widths, underestimating buffer space or underflowing the buffer-growth target. Exposure requires an application to pass attacker-controlled indentation, or a fixed negative indent, to dump, dumps, or encode on nested data.

The record

CVE
CVE-2026-32875
Published
Mar 20, 2026
Updated
Mar 20, 2026
Vendor
UltraJSON
Product
UltraJSON
Classifications
CWE-787, CWE-190, CWE-835, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 5.1.0, < 5.12.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

UltraJSON · UltraJSONversion=>= 5.1.0, < 5.12.0

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5Red Hat Product SecurityCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-190Integer Overflow or Wraparound
CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

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