PatchTheCVECVE-2023-22899: Zip4j through 2.11.2, as used in Threema and other products, does not always check the MAC when decrypting a Z
CVE-2023-22899 is a medium-severity flaw (CVSS 5.9) affecting zip4j. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Zip4j through 2.11.2, as used in Threema and other products, does not always check the MAC when decrypting a ZIP archive.
Why this priority
- Public exploit reference
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.9 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.6% (top 49%) |
| CISA exploited list | No |
| Weakness | CWE-346 |
| Published | 2023-01-10 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2023-22899?
zip4j: upgrade to newer than 2.11.2. Exact commands for each OS are on this page.
Is CVE-2023-22899 being exploited?
CVE-2023-22899 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2023-22899 affect?
CVE-2023-22899 affects zip4j. Severity is medium (CVSS 5.9). Zip4j through 2.11.2, as used in Threema and other products, does not always check the MAC when decrypting a ZIP archive.
How urgent is CVE-2023-22899?
Priority 43/100. Public exploit reference; Remotely exploitable, no login, no user action