The openexr library, used for the EXR image file format, contains an out-of-bounds read vulnerability in the IDManifest::init() function. When processing prefix-compressed strings, if the previous string exceeds 255 bytes, the next string should start with a 2-byte prefix length. However, the code reads these two bytes without confirming the current string's length, potentially causing an out-of-bounds read. This flaw affects versions 3.0.0 up to but not including 3.2.9, 3.3.0 up to but not including 3.3.11, and 3.4.0 up to but not including 3.4.11. The vulnerability has been addressed in versions 3.2.9, 3.3.11, and 3.4.11.

This vulnerability allows an attacker to cause an out-of-bounds read, which may lead to application crashes or exposure of sensitive memory content. The CVSS 4.0 score of 8.8 reflects a high severity with network attack vector, no privileges or user interaction required, and high impact on confidentiality and availability.

A fix is available in openexr versions 3.2.9, 3.3.11, and 3.4.11. Users and organizations should upgrade to these patched versions to remediate this vulnerability. No additional mitigation steps are indicated by the vendor advisory.