Authenticated code execution via plugin path traversal
Published Apr 17, 2026 · Updated Apr 17, 2026
Path traversal in Firebird before 3.0.14, 4.0.0 through 4.0.6, and 5.0.0 through 5.0.3 allows remote authenticated users to execute code. PluginLoadInfo appends the supplied ENGINE name to the plugins directory and passes the unresolved path to dlopen or LoadLibraryEx, allowing separators and .. components to escape that directory. CREATE FUNCTION privilege and a reachable shared library are required; its initialization code then runs as the Firebird server account before plugin validation.
Summary
What happened
Path traversal in Firebird before 3.0.14, 4.0.0 through 4.0.6, and 5.0.0 through 5.0.3 allows remote authenticated users to execute code. PluginLoadInfo appends the supplied ENGINE name to the plugins directory and passes the unresolved path to dlopen or LoadLibraryEx, allowing separators and .. components to escape that directory. CREATE FUNCTION privilege and a reachable shared library are required; its initialization code then runs as the Firebird server account before plugin validation.
The record
- CVE
- CVE-2026-40342
- Published
- Apr 17, 2026
- Updated
- Apr 17, 2026
- Vendor
- Firebird Project
- Product
- Firebird
- Classifications
- CWE-94, CWE-73, CWE-22, CWE-427, CAPEC-126, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 17, 2026CVE publishedPublication date reported by the CVE source.
- Apr 17, 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=< 3.0.14
- Affected versionversion=>= 4.0.0, < 4.0.7
- Affected versionversion=>= 5.0.0, < 5.0.4
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.
Weakness, pattern, technique
Public exploit references
- Firebird external-engine path traversal minimal reproductionproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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