CVE-2026-28214
Integer Overflow in Firebird ClumpletReader Causes Denial of Service
Publication date: 2026-04-17
Last updated on: 2026-04-24
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| firebirdsql | firebird | to 3.0.14 (exc) |
| firebirdsql | firebird | From 4.0.0 (inc) to 4.0.7 (exc) |
| firebirdsql | firebird | From 5.0.0 (inc) to 5.0.4 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-835 | The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. |
| CWE-190 | The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in Firebird, an open-source relational database management system, in versions prior to 5.0.4, 4.0.7, and 3.0.14. The issue occurs in the ClumpletReader::getClumpletSize() function, which can overflow the totalLength value when parsing a Wide type clumplet. This overflow causes an infinite loop.
An authenticated user with INSERT privileges on any table can exploit this vulnerability by sending a specially crafted Batch Parameter Block, which triggers the infinite loop and leads to a denial of service (DoS) against the server.
The vulnerability has been fixed in Firebird versions 5.0.4, 4.0.7, and 3.0.14.
How can this vulnerability impact me? :
This vulnerability can be exploited to cause a denial of service (DoS) on the Firebird database server. Specifically, an authenticated user with INSERT privileges can trigger an infinite loop in the server process, potentially making the database unavailable or unresponsive.
This could disrupt applications and services relying on the database, leading to downtime and impacting business operations.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, you should upgrade Firebird to one of the fixed versions: 5.0.4, 4.0.7, or 3.0.14.
Since the vulnerability can be exploited by an authenticated user with INSERT privileges, consider restricting such privileges until the upgrade is applied.