Unauthenticated server crash via malformed op_slice packet
Published Apr 17, 2026 · Updated Apr 17, 2026
Null pointer dereference in Firebird before 3.0.14, 4.0.0 through 4.0.6, and 5.0.0 through 5.0.3 allows remote attackers to crash the server. The network protocol passes an unprepared slice_response->p_slr_sdl containing a null pointer through xdr_slice() to SDL_info(), which dereferences it. No authentication or user interaction is required; one crafted packet to the server port triggers SIGSEGV and interrupts database availability.
Summary
What happened
Null pointer dereference in Firebird before 3.0.14, 4.0.0 through 4.0.6, and 5.0.0 through 5.0.3 allows remote attackers to crash the server. The network protocol passes an unprepared slice_response->p_slr_sdl containing a null pointer through xdr_slice() to SDL_info(), which dereferences it. No authentication or user interaction is required; one crafted packet to the server port triggers SIGSEGV and interrupts database availability.
The record
- CVE
- CVE-2026-28212
- Published
- Apr 17, 2026
- Updated
- Apr 17, 2026
- Vendor
- Firebird Project
- Product
- Firebird
- Classifications
- CWE-476, 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
Compare your product and version with the public record. A matching version still requires validation against your environment.
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
- One packet DoS proof of conceptproof 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
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo