Quick answers
- Is CVE-2026-54903 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-54903 being exploited in the wild.
- How severe is CVE-2026-54903?
- High severity, with a CVSS score of 4, published 1 July 2026.
- Which products and versions are affected?
- oj (RubyGems) < 3.17.2, ECOSYSTEM:introduced=0,fixed=3.17.3.
- Is there a fix for CVE-2026-54903?
- Yes. oj (RubyGems): upgrade to 3.17.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-54903 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-54903?
- Check whether you run oj (RubyGems) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- oj (RubyGems): upgrade to 3.17.3 or later
bundle update oj
Technical details
An integer overflow exists in the `read_escaped_str` function within `parse.c` when calculating string length. When a JSON string exceeds 2 GB, the length calculation wraps to a negative value, which is then cast to a large `size_t` in `buf_append_string` (buf.h). This results in an out-of-bounds `memcpy` operation, leading to heap corruption or an immediate process crash (DoS). The vulnerability is reachable via the `Oj.load` method and has been addressed in version 3.17.2.
Affected products
- ohler55 oj < 3.17.2
Identifiers
- CVE-2026-54903
- GHSA-475m-ph3x-64gp
Timeline
- 2026-06-16: advisory: GitHub security advisory published
- 2026-06-30: patched: Fix released in version 3.17.2
- 2026-07-01: disclosed: NVD publication date