VulnerabilityDeferred

CVE-2026-54899

Prior to version 3.17.2, disabling symbol_keys on a reused Oj::Parser instance triggers a heap use-after-free.

MEDIUM 6.3EPSS 0.43%

Does this matter?

Lower severity and a low EPSS score (0.43%). Track it; it rarely justifies an emergency change on its own.

Description

Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. Prior to version 3.17.2, disabling symbol_keys on a reused Oj::Parser instance triggers a heap use-after-free. When symbol_keys is toggled from true to false, opt_symbol_keys_set frees the internal key cache (cache_free) but does not clear the pointer. The next parse call reads from the freed cache via cache_intern, producing a use-after-free. This issue has been fixed in version 3.17.2.

CVSS 4.0: 6.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/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/M
EPSS: 0.43% probability · 36th percentile
CISA KEV: Not listed
Weakness: CWE-416
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.