zlib has 6 CVEs on record between 2017 and 2026. 1 was published in the last 90 days. The median CVSS is 9.3 (critical), with 3 rated critical. None have a confirmed exploitation report. The most common weakness class is CWE-787 (3).
CVEs per month
Last 12 months, by publish date
- Exploited share
- 0% vs 1% corpus
- Median CVSS
- 9.3
- Publish → KEV
- —
- Last 90 days
- 1 prev 0
Weakness classes
Products
- zlib 6
Worst active — by depth score
CVE-2022-37434Critical· 9.8zlib 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 field70CVE-2023-45853Critical· 9.8MiniZip 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 field55CVE-2016-9841Critical· 9.8inffast.c in zlib 1.2.8 might allow context-dependent attackers to have unspecified impact by leveraging improper pointer arithmetic.55CVE-2026-76844High· 7.4zlib 1.2.11 through 1.3.2 contains a heap buffer overflow: after an underlying write() fails, gz_write() returns without resetting strm.next_in, leaving it pointed at the caller's buffer53CVE-2016-9842High· 8.8The inflateMark function in inflate.c in zlib 1.2.8 might allow context-dependent attackers to have unspecified impact via vectors involving left shifts of negative integers.49
zlib vulnerabilities
CVEs affecting zlib, newest first. Open any entry for full detail, references, and exploit status.
6 CVEsRSS
CVE-2026-76844High· 7.4PoCzlib 1.2.11 through 1.3.2 contains a heap buffer overflow: after an underlying write() fails, gz_write() returns without resetting strm.next_in, leaving it pointed at the caller's buffer
zlib 1.2.11 through 1.3.2 contains a heap buffer overflow: after an underlying write() fails, gz_write() returns without resetting strm.next_in, leaving it pointed at the caller's buffer. A later gz* write call then derives a position fr…
CVE-2026-22184High· 7.8zlib versions up to and including 1.3.1.2 include a global buffer overflow in the untgz utility located under contrib/untgz
zlib versions up to and including 1.3.1.2 include a global buffer overflow in the untgz utility located under contrib/untgz. The vulnerability is limited to the standalone demonstration utility and does not affect the core zlib compressi…
CVE-2023-45853Critical· 9.8⚖ disputedMiniZip 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
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: pymini…
CVE-2022-37434Critical· 9.8PoC⚖ disputedzlib 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
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 af…
CVE-2016-9842High· 8.8The inflateMark function in inflate.c in zlib 1.2.8 might allow context-dependent attackers to have unspecified impact via vectors involving left shifts of negative integers.
The inflateMark function in inflate.c in zlib 1.2.8 might allow context-dependent attackers to have unspecified impact via vectors involving left shifts of negative integers.
CVE-2016-9841Critical· 9.8inffast.c in zlib 1.2.8 might allow context-dependent attackers to have unspecified impact by leveraging improper pointer arithmetic.
inffast.c in zlib 1.2.8 might allow context-dependent attackers to have unspecified impact by leveraging improper pointer arithmetic.