When EXIF extension is parsing EXIF information from an image, e.g. via exif_read_data() function, in versions 7.1.x below 7.1.30, 7.2.x below 7.2.19 and 7.3.x below 7.3.6 it is possible to supply it with data what will cause it to read past the allocated buffer. This may lead to information disclosure or crash.
Source: NIST
CVE-2019-11040