🛡️ CVE-2026-54900 on Debian — ruby-oj
Description
Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.2, when in usual mode with create_id enabled, Oj::Parser#parse is vulnerable to heap corruption via a negative-size memcpy. When a JSON object key is exactly 65,535 bytes long, an integer truncation in form_attr (usual.c:63) converts the length to -1 before passing it to memcpy. This causes memcpy to copy SIZE_MAX bytes (interpreted as a huge size_t), corrupting heap memory and crashing the process. The issue has been fixed in version 3.17.2.
Distribution advisory
This page covers CVE-2026-54900 as tracked by Debian, for the package ruby-oj. The fix is available in version 3.17.3-1; earlier versions remain affected.
How this vulnerability can be exploited
This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability low.
Weakness class
DEBIAN-CVE-2026-54900 is classified as CWE-416: Use After Free. Memory is used after being released, so its contents may already belong to something else.
Affected software
DEBIAN-CVE-2026-54900 is recorded against 1 package.
- ruby-oj (fixed in 3.17.3-1)
Timeline and source
Published on 1 July 2026 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
Details
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| ruby-oj | — | 3.17.3-1 |
References
Similar Threats
- Unknown DEBIAN-CVE-2026-54500
- Unknown DEBIAN-CVE-2026-54502
- Unknown DEBIAN-CVE-2026-54592
- Unknown DEBIAN-CVE-2026-54896
- Unknown DEBIAN-CVE-2026-54897
Site Security Check
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