VulnerabilityPublished 1 Jul 2026

CVE-2026-54900: Integer Overflow or Wraparound in ohler55 oj

Affects ojSource GCVE Database

Not known to be exploited : upgrade to 3.17.2 when convenient.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Medium

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.17.2

Exploitation evidence

Disclosed: evidence found.
CVE published 1 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade oj to 3.17.2.

Affected software

Product	Affected	Fixed in
RubyGemsoj`pkg:gem/oj`Other threats	Affected <3.17.2	Fixed in 3.17.2
Ubuntu 14.04 LTSruby-oj`pkg:deb/ubuntu/ruby-oj?arch=source&distro=trusty`Other threats	Affected 2.0.10-1 – 2.5.3-1 4 affected builds	Fixed in–
Ubuntu 16.04 LTSruby-oj`pkg:deb/ubuntu/ruby-oj?arch=source&distro=xenial`Other threats	Affected 2.12.10-3 – 2.12.10-4build1 4 affected builds	Fixed in–
Ubuntu 18.04 LTSruby-oj`pkg:deb/ubuntu/ruby-oj?arch=source&distro=bionic`Other threats	Affected =2.17.4-1 =3.4.0-1 =3.4.0-1build1	Fixed in–
Ubuntu 20.04 LTSruby-oj`pkg:deb/ubuntu/ruby-oj?arch=source&distro=focal`Other threats	Affected 3.8.1-1 – 3.10.1-1build1 5 affected builds	Fixed in–
Ubuntu 22.04 LTSruby-oj`pkg:deb/ubuntu/ruby-oj?arch=source&distro=jammy`Other threats	Affected 3.11.0-1 – 3.13.9-1build1 5 affected builds	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available in Oj version 3.17.2. Users should upgrade to version 3.17.2 or later to remediate this vulnerability. No other mitigation or workaround is indicated.

Description

CVE-2026-54900 is an integer overflow vulnerability in the Oj Ruby gem used for JSON parsing and object marshalling. Versions prior to 3.17.2 are affected when a JSON object key is exactly 65,535 bytes long, causing heap corruption and process crashes due to a negative size passed to memcpy. The issue is fixed in version 3.17.2.

CWE-190Integer Overflow or Wraparound (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
Requirements
Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V5.4.3 (opens in a new tab)
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
Attack patterns
Forced Integer Overflow (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-787Out-of-bounds Write (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #5
The product writes data past the end, or before the beginning, of the intended buffer.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 25 Oct 2026, 23:23 UTC

WeaknessesCWE-190, CWE-787

Technical details

References

Community reviews

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