Zlib: community verdicts

3 notable / known-exploited Zlib CVEs the community has triaged.

ⓘ Not an exhaustive list: we focus on the findings that matter (exploited / notable). For every Zlib CVE, see NVD ↗.

CVE-2018-25032HIGH 7.5Likely realEPSS 52%
zlib before 1.2.12 allows memory corruption when deflating (i.e., when compressing) if the input has many distant matches.
CVE-2022-37434CRIT 9.8EPSS 16%
zlib through 1.2.12 has a heap-based buffer over-read or buffer overflow in inflate in inflate.c via a large gzip header extra field. NOTE: only applications that call inflateGetHeader are affected. Some common applications bundle the affected zlib source code but may be unable to call inflateGetHeader (e.g., see the nodejs/node reference).
CVE-2023-45853CRIT 9.8Real · low riskEPSS 3%
MiniZip in zlib through 1.3 has an integer overflow and resultant heap-based buffer overflow in zipOpenNewFileInZip4_64 via a long filename, comment, or extra field. NOTE: MiniZip is not a supported part of the zlib product. NOTE: pyminizip through 0.2.6 is also vulnerable because it bundles an affected zlib version, and exposes the applicable MiniZip code through its compress API.