CVE-2026-42216 OpenEXR: Out-of-bounds read in `IDManifest::init()` during prefix expansion
An out-of-bounds read in OpenEXR allows attackers to cause denial of service or disclose memory contents via crafted image files.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42216?
CVE-2026-42216 is a high-severity memory corruption vulnerability in Openexr Openexr, published on 7 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From versions 3.0.0 to before 3.2.9, 3.3.0 to before 3.3.11, and 3.4.0 to before 3.4.11, IDManifest::init() reconstructs strings from a prefix-compressed representation. If the previous string is longer than 255 bytes, the next string is expected to begin with a 2-byte prefix length. The code reads stringList[i][0] and stringList[i][1] without checking that the current string has at least two bytes. This issue has been patched in versions 3.2.9, 3.3.11, and 3.4.11.
Which versions are affected by CVE-2026-42216?
It affects 1 product.
Products include Openexr Openexr.
How do I fix CVE-2026-42216?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-42216 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42216 exists.
Other vulnerabilities in Openexr Openexr
- CVE-2023-5841 OpenEXR Heap Overflow in Scanline Deep Data Parsing
- CVE-2026-41142 OpenEXR is Vulnerable to Integer overflow in ImageChannel::resize leads to heap OOB write via OpenEXRUtil public API
- CVE-2017-9111 OpenEXR invalid write
- CVE-2017-9113 Memory corruption in n/a
- CVE-2017-9115 Memory corruption in n/a
Sources
Also known as BELL-CVE-2026-42216, DEBIAN-CVE-2026-42216, ECHO-7ba5-1829-1400, GHSA-65j8-95g9-jgj4, JLSEC-2026-810, ROOT-OS-DEBIAN-11-CVE-2026-42216 and 3 more.