CVE-2026-18929: Resource Exhaustion in Carbone
Carbone is vulnerable to Denial of Service due to lack of protection against zip bombs when processing .docx files. The library uses yazl for zip decompression without validating entry sizes, allowing an attacker to supply a malicious .docx file containing a zip bomb that decompresses to a significantly larger size, causing excessive memory consumption and crashing the application server.
The issue was fixed in versions: 3.8.2, 4.26.3 and 5.4.4. The fix is available across all distribution types.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Carboneto a version that resolves this vulnerability.Fixed in 3.8.2 - Upgrade
Upgrade
Carboneto a version that resolves this vulnerability.Fixed in 4.26.3 - Upgrade
Upgrade
Carboneto a version that resolves this vulnerability.Fixed in 5.4.4
Event History
Frequently Asked Questions
What conditions are required for exploitation?
Applications are exposed when they process .docx files with affected Carbone versions. An attacker needs to provide a malicious .docx file containing a zip bomb for the application to process.
Which versions address the issue?
The issue is fixed in Carbone versions 3.8.2, 4.26.3, and 5.4.4, with fixes available across all distribution types. Upgrade to the applicable fixed release.
What can be done if patching is not immediately possible?
Until the upgrade is deployed, avoid processing untrusted .docx files, since the denial of service is triggered by a malicious .docx zip bomb during processing.