Service interruption via stale symbol-key cache
Published Jun 30, 2026 · Updated Jun 30, 2026
Use-after-free in Oj before 3.17.2 allows attackers to interrupt service by triggering a stale parser-cache read. opt_symbol_keys_set frees key_cache without clearing its pointer, and the next parse reaches cache_intern through cache_key and reads the freed allocation. Exploitation requires application code that reuses an Oj::Parser, changes symbol_keys from true to false, and then parses attacker-influenced JSON.
Summary
What happened
Use-after-free in Oj before 3.17.2 allows attackers to interrupt service by triggering a stale parser-cache read. opt_symbol_keys_set frees key_cache without clearing its pointer, and the next parse reaches cache_intern through cache_key and reads the freed allocation. Exploitation requires application code that reuses an Oj::Parser, changes symbol_keys from true to false, and then parses attacker-influenced JSON.
The record
- CVE
- CVE-2026-54899
- Published
- Jun 30, 2026
- Updated
- Jun 30, 2026
- Vendor
- Peter Ohler
- Product
- Oj
- Classifications
- CWE-416, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 30, 2026CVE publishedPublication date reported by the CVE source.
- Jun 30, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 3.17.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- Oj::Parser symbol_keys use-after-free reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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