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Fencer Vulns
medium 6.5

CVE-2026-34378 json

OpenEXR has a signed integer overflow in generic_unpack() when parsing EXR files with crafted negative dataWindow.min.x

published 2026-04-06 7 mo ago modified 2026-10-26 13 d ago also EUVD-2026-19303 , JLSEC-2026-142

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 19%
public exploits
0
none known

Summary

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.4.0 to before 3.4.9, a missing bounds check on the dataWindow attribute in EXR file headers allows an attacker to trigger a signed integer overflow in generic_unpack(). By setting dataWindow.min.x to a large negative value, OpenEXRCore computes an enormous image width, which is later used in a signed integer multiplication that overflows, causing the process to terminate with SIGILL via UBSan. This vulnerability is fixed in 3.4.9.

Patch / fix

  • julia OpenEXR_jll 3.4.9+0
  • openexr openexr 3.4.9
  • openexr Debian 14 3.4.14-0.1

debian advisories DEBIAN-CVE-2026-34378

  • openexr openSUSE Tumbleweed 3.4.9-1.1

opensuse advisories openSUSE-SU-2026:10505-1

  • openexr Alpine 3.22 3.3.11-r0
  • openexr Alpine 3.23 3.4.13-r0
  • openexr Alpine 3.24 3.4.10-r0

alpine advisories ALPINE-CVE-2026-34378

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-34378 updated cvss 6.5

OpenEXR: OpenEXR: Denial of Service via crafted EXR file integer overflow

  • Red Hat Enterprise Linux 6 OpenEXR, OpenEXR-libs Red Hat Enterprise Linux 7 OpenEXR, OpenEXR-libs Red Hat Enterprise Linux 8 OpenEXR, OpenEXR-libs Red Hat Enterprise Linux 9 openexr, openexr-libs Red Hat Enterprise Linux 10 openexr
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-v76p-4qvv-vh4g referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
OSV 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
julia OpenEXR_jll
>=3.4.4+0, <3.4.9+0
3.4.9+0

Affected products

  • AcademySoftwareFoundation openexr

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.