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CVE Record

CVE-2026-34588: OpenEXR has a signed 32-bit Overflow in PIZ Decoder Leads to OOB Read/Write

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.1.0 to before 3.2.7, 3.3.9, and 3.4.9, internal_exr_undo_piz() advances the working wavelet pointer with signed 32-bit arithmetic. Because nx, ny, and wcount are int, a crafted EXR file can make this product overflow and wrap. The next channel then decodes from an incorrect address. The wavelet decode path operates in place, so this yields both out-of-bounds reads and out-of-bounds writes. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9.

HighCVSS 8.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

OpenEXR can be corrupted by a specially crafted EXR image when vulnerable versions decode PIZ-compressed data. The bug can make the decoder read and write outside intended memory. This matters for render, media, design, and asset-processing systems that accept EXR files, especially from external or semi-trusted sources.

Executive priority

Treat this as a high-priority media-processing patch, not a broad internet worm scenario. Prioritize systems that receive EXR files from customers, vendors, artists, automated uploads, or shared production pipelines.

Technical view

In OpenEXR 3.1.0 through affected 3.4.x releases, internal_exr_undo_piz() advances a wavelet working pointer using signed 32-bit arithmetic. Crafted nx, ny, and wcount values can overflow and wrap the pointer, causing the next channel decode to use an incorrect address and perform out-of-bounds reads and writes.

Likely exposure

Exposure is most likely where OpenEXR 3.1.0 through vulnerable 3.4.x versions process EXR files in user workstations, render pipelines, content ingestion services, converters, or bundled third-party applications.

Exploitation context

The CVSS vector indicates no privileges are required, low complexity, and user interaction is required. The source bundle does not show CISA KEV listing or confirmed active exploitation. Practical risk depends on whether attackers can get crafted EXR files processed by vulnerable systems.

Researcher notes

Key uncertainty is exploitability beyond memory corruption: the sources establish out-of-bounds read/write and high CVSS impact, but do not provide proof of exploitation. Focus validation on exact OpenEXR linkage and reachable PIZ decode paths rather than package names alone.

Mitigation direction

  • Upgrade OpenEXR to 3.2.7, 3.3.9, 3.4.9, or later supported releases.
  • Apply relevant Red Hat security advisories where OpenEXR is supplied by Red Hat packages.
  • Inventory applications, containers, and static builds that bundle OpenEXR independently of system packages.
  • Reduce or isolate processing of untrusted EXR files until vulnerable instances are remediated.
  • Monitor upstream and operating-system vendor guidance for branch-specific update instructions.

Validation and detection

  • Check installed and bundled OpenEXR versions against the affected ranges in the advisory.
  • Confirm patched systems report OpenEXR 3.2.7, 3.3.9, 3.4.9, or later.
  • Review asset-ingestion and rendering workflows for places that automatically process EXR files.
  • Verify Red Hat package status against applicable RHSA advisories or CSAF/VEX data.
  • Document any exception where EXR processing is unreachable or isolated from untrusted input.
Prepared
Confidence
high
Sources
11

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-125: 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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cwe · low confidence lookup

CWE-787: 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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cve · low confidence lookup

CVE-2026-34588 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
21Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: 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
8.6CVSS 4.0HighCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——GitHub_M

Vulnerability scoring details

Base CVSS 4.0 score

8.6High
CVSS 4.0 vector shape for CVE-2026-34588Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/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: Arbitrary code execution and information disclosure via crafted EXR file
other:Red Hat severity ratingcvssV3_1
  • 2026-04-06T16:02:38.673Z: Reported to Red Hat.
  • 2026-04-06T15:31:57.602Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
AcademySoftwareFoundationopenexr>= 3.1.0, <= 3.1.13, >= 3.2.0, < 3.2.7, >= 3.3.0, < 3.3.9, >= 3.4.0, < 3.4.9Listed
Weakness

CWE details

CWE-125CWE-190CWE-787

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