zlib 1.2.13 release notes

October 13, 2022

Version 1.2.13 has these key updates:

Fix a bug when getting a gzip header extra field with inflateGetHeader(). This remedies CVE-2022-37434.
Fix a bug in block type selection when Z_FIXED used. Now the smallest block type is selected, for better compression.
Fix a configure issue that discarded the provided CC definition.
Correct incorrect inputs provided to the CRC functions. This mitigates a bug in Java.
Repair prototypes and exporting of the new CRC functions.
Fix inflateBack to detect invalid input with distances too far.

Due to the first bug fix, any installations of 1.2.12 or earlier should be replaced with 1.2.13.

madler/zlib v1.2.13 zlib 1.2.13 on GitHub