firebird: Improper Handling of Syntactically Invalid Structure
CVE-2026-34232 is a high-severity improper handling of syntactically invalid structure vulnerability in firebird from FirebirdSQL, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected firebird versions: >= 3.0.0, < 3.0.14; >= 4.0.0, < 4.0.7; >= 5.0.0, < 5.0.4. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.48% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of firebird you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| FirebirdSQL | firebird | >= 3.0.0, < 3.0.14; >= 4.0.0, < 4.0.7; >= 5.0.0, < 5.0.4 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (github.com).
Official description
Firebird is an open-source relational database management system. In versions prior to 5.0.4, 4.0.7 and 3.0.14, the xdr_status_vector() function does not handle the isc_arg_cstring type when decoding an op_response packet, causing a server crash when one is encountered in the status vector. An unauthenticated attacker can exploit this by sending a crafted op_response packet to the server. This issue has been fixed in versions 5.0.4, 4.0.7 and 3.0.14.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Handling of Syntactically Invalid Structure
The product does not handle or incorrectly handles input that is not syntactically well-formed with respect to the associated specification.
More Improper Handling of Syntactically Invalid Structure vulnerabilities (CWE-228)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/FirebirdSQL/firebird/releases/tag/v3.0.14Release Notes
- github.com/FirebirdSQL/firebird/releases/tag/v4.0.7Release Notes
- github.com/FirebirdSQL/firebird/releases/tag/v5.0.4Release Notes
Other vulnerabilities in firebird
- 9.9 Critical severity
- 7.5 High severity
- 7.5 High severity
- 8.2 High severity
- 7.5 High severity
- 8.2 High severity
Recent Improper Handling of Syntactically Invalid Structure vulnerabilities
- 7.7 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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