Zlib vulnerabilities
We track 3 vulnerabilities in Zlib products. 3 are rated high or critical, and none are known to be exploited. The most recent was published on September 3, 2026.
Latest Zlib vulnerabilities
- 7.4 High severity
zlib: Out-of-bounds Write
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 from the stale pointer an
- 9.8 Critical severity
zlib: Integer Overflow or Wraparound
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 al
- 9.8 Critical severity
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP: Out-of-bounds Write
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