Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.3, Oj.load in :object mode reads uninitialized stack memory (and, for long keys, reads out of bounds) when parsing a JSON object whose key is 254 bytes or longer. The interned bytes can surface to the caller, disclosing process stack memory. In ext/oj/intern.c, form_attr() handles the long-key path by allocating a heap buffer, `b`, populating it with the attribute name, and then freeing it — but it passed the uninitialized stack buffer buf (not b) to rb_intern3(). rb_intern3 therefore reads len + 1 bytes of uninitialized stack memory. When the key length is >= 256, it also reads out of bounds past the 256-byte buf. The resulting bytes are interned and can reach the caller via the produced Symbol or via the EncodingError message raised on invalid UTF-8, leaking process stack contents. This issue has been fixed in version 3.17.3.

An update of the rubygem package has been released.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to     3.17.3, Oj.load in :object mode reads uninitialized stack memory (and, for long keys, reads out of bounds)     when parsing a JSON object whose key is 254 bytes or longer. The interned bytes can surface to the caller,     disclosing process stack memory. In ext/oj/intern.c, form_attr() handles the long-key path by allocating a     heap buffer, `b`, populating it with the attribute name, and then freeing it  but it passed the     uninitialized stack buffer buf (not b) to rb_intern3(). rb_intern3 therefore reads len + 1 bytes of     uninitialized stack memory. When the key length is >= 256, it also reads out of bounds past the 256-byte     buf. The resulting bytes are interned and can reach the caller via the produced Symbol or via the     EncodingError message raised on invalid UTF-8, leaking process stack contents. This issue has been fixed     in version 3.17.3. (CVE-2026-54500)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to
    3.17.3, Oj.load in :object mode reads uninitialized stack memory (and, for long keys, reads out of bounds)
    when parsing a JSON object whose key is 254 bytes or longer. The interned bytes can surface to the caller,
    disclosing process stack memory. In ext/oj/intern.c, form_attr() handles the long-key path by allocating a
    heap buffer, `b`, populating it with the attribute name, and then freeing it — but it passed the
    uninitialized stack buffer buf (not b) to rb_intern3(). rb_intern3 therefore reads len + 1 bytes of
    uninitialized stack memory. When the key length is >= 256, it also reads out of bounds past the 256-byte
    buf. The resulting bytes are interned and can reach the caller via the produced Symbol or via the
    EncodingError message raised on invalid UTF-8, leaking process stack contents. This issue has been fixed
    in version 3.17.3. (CVE-2026-54500)

ID	Name	Product	Family	Severity
325969	Photon OS 4.0: Rubygem PHSA-2026-4.0-1052	Nessus	PhotonOS Local Security Checks	high
325967	Photon OS 5.0: Rubygem PHSA-2026-5.0-0917	Nessus	PhotonOS Local Security Checks	medium
324703	Linux Distros Unpatched Vulnerability : CVE-2026-54500	Nessus	Misc.	medium
443665	SCA: security update for oj (GHSA-fm7p-mprw-wjm9)	Tenable Cloud Security	SCA Checks	medium
443665	SCA: security update for oj (GHSA-fm7p-mprw-wjm9)	Tenable Self-Hosted Container Security	SCA Checks	medium

Detections

Analytics

CVE-2026-54500

medium

Tenable Plugins

high

medium

medium

medium

medium