Server crash via unhandled status-vector type
Published Apr 17, 2026 · Updated Apr 17, 2026
Denial of service in Firebird before 3.0.14, 4.0.7, and 5.0.4 allows remote attackers to crash the server via a crafted op_response packet. The xdr_status_vector() decoder does not handle the isc_arg_cstring tag and misparses a client-supplied status vector before loopThread() drops the invalid response. No authentication or user interaction is required; sending the packet to a listening Firebird service interrupts availability by terminating the server process.
Summary
What happened
Denial of service in Firebird before 3.0.14, 4.0.7, and 5.0.4 allows remote attackers to crash the server via a crafted op_response packet. The xdr_status_vector() decoder does not handle the isc_arg_cstring tag and misparses a client-supplied status vector before loopThread() drops the invalid response. No authentication or user interaction is required; sending the packet to a listening Firebird service interrupts availability by terminating the server process.
The record
- CVE
- CVE-2026-34232
- Published
- Apr 17, 2026
- Updated
- Apr 17, 2026
- Vendor
- FirebirdSQL
- Product
- Firebird
- Classifications
- CWE-228, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
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=>= 3.0.0, < 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 op_response denial-of-service Python scriptfunctional · demonstrated
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Technologies
Your stack
See the directory against your own environment.
Your stack
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