CVE-2026-44663

OpenEXR: Integer overflow in the HTJ2K decoder leads to heap-buffer-overflow

HIGH
7.1
CVSS Score
Published: June 18, 2026 at 08:20 PM UTC
Updated: October 26, 2026 at 11:10 AM UTC
2 products affected across 2 vendorsOpenexrOpenexr

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Severity
HIGH7.1
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

OpenEXR is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. In versions 3.4.0 through 3.4.11, an integer overflow in ht_undo_impl() in src/lib/OpenEXRCore/internal_ht.cpp leads to a heap-buffer overflow when decoding a crafted HTJ2K-compressed EXR file. decode->channels[i].width (int32_t) is multiplied by bytes_per_element in 32-bit signed arithmetic. With large widths (e.g., >= 536870912 for FLOAT data), this overflows, producing a corrupted offset that is later used for pointer arithmetic and can cause a heap out-of-bounds write. The same unchecked multiplication pattern appears in two other HTJ2K paths (bytes-per-line accumulation and pixel-line pointer advancement). As with related CVE-2026-34378 through CVE-2026-34589 fixes in other codecs, validating only after the multiplication is too late because the value may already be overflowed. This issue has been fixed in version 3.4.12.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

3.4.0 ≤ v < 3.4.12
Affected range stops below 3.4.12, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.4.11, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

x_refsource_CONFIRMExploitMitigationPatchVendor Advisory
Source: cverecord
https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-777r-f9x8-7r84

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-190CWE-787

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