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CVE Record

CVE-2026-34545: OpenEXR: integer overflow lead to OOB in HTJ2K decoder

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From version 3.4.0 to before version 3.4.7, an attacker providing a crafted .exr file with HTJ2K compression and a channel width of 32768 can write controlled data beyond the output heap buffer in any application that decodes EXR images. The write primitive is 2 bytes per overflow iteration or 4 bytes (by another path), repeating for each additional pixel past the overflow point. In this context, a heap write overflow can lead to remote code execution on systems. This issue has been patched in version 3.4.7.

HighCVSS 8.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A crafted EXR image can trigger memory corruption in vulnerable OpenEXR versions when HTJ2K compression is decoded. Any application that opens or processes untrusted EXR files through OpenEXR 3.4.0 to 3.4.6 could face code execution risk. The issue is fixed in OpenEXR 3.4.7.

Executive priority

Treat this as a high-priority media-processing risk where EXR files cross trust boundaries. Patch exposed ingestion and rendering workflows first, especially automated services that handle customer, partner, or internet-supplied image assets.

Technical view

CVE-2026-34545 is an integer overflow leading to heap out-of-bounds writes in OpenEXR's HTJ2K decoder. A crafted .exr file using HTJ2K compression and channel width 32768 can write controlled data beyond the output heap buffer. The CVSS 3.1 score is 8.8 with user interaction required.

Likely exposure

Exposure is most likely in media pipelines, render tooling, asset ingestion services, or desktop applications that decode untrusted EXR files using OpenEXR 3.4.0 through 3.4.6.

Exploitation context

The source bundle does not show KEV listing or confirmed active exploitation. Exploitation requires a target application or user workflow to decode a malicious EXR file with the vulnerable HTJ2K path.

Researcher notes

Key constraints are HTJ2K compression and channel width 32768. The advisory describes controlled heap writes of 2 or 4 bytes per overflow iteration. Sources support RCE potential, but do not establish active exploitation in the provided bundle.

Mitigation direction

  • Upgrade OpenEXR to version 3.4.7 or later.
  • Identify bundled or statically linked OpenEXR copies in applications.
  • Temporarily restrict untrusted EXR or HTJ2K-compressed EXR processing where patching is delayed.
  • Check operating system and vendor advisories for packaged fixes.
  • Prioritize systems that automatically process externally supplied media files.

Validation and detection

  • Confirm deployed OpenEXR versions are not 3.4.0 through 3.4.6.
  • Review SBOMs and build manifests for direct or transitive OpenEXR use.
  • Verify asset ingestion paths reject or sandbox untrusted EXR files until patched.
  • Check vendor package status for applications embedding OpenEXR.
  • Confirm upgraded systems report OpenEXR 3.4.7 or later.
Prepared
Confidence
high
Sources
8

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-122: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cwe · low confidence lookup

CWE-1284: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cwe · low confidence lookup

CWE-190: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2026-34545 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
7Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: noTechnical Impact: total

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.8CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H2.85.9redhat-SADP
8.4CVSS 4.0HighCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——GitHub_M

Vulnerability scoring details

Base CVSS 4.0 score

8.4High
CVSS 4.0 vector shape for CVE-2026-34545Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPOpenEXR: OpenEXR: Remote code execution via crafted EXR files
other:Red Hat severity ratingcvssV3_1
  • 2026-04-01T22:02:15.810Z: Reported to Red Hat.
  • 2026-04-01T20:51:45.884Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
AcademySoftwareFoundationopenexr>= 3.4.0, < 3.4.7Listed
Weakness

CWE details

CWE-122CWE-1284CWE-190

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.