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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

A specially crafted EXR image can trigger unsafe memory access when opened or processed by vulnerable OpenEXR versions. This may expose data, corrupt processing results, or crash the affected application. Risk is greatest in services and creative pipelines that accept EXR files from untrusted sources.

Executive priority

Treat remediation as high priority, especially for public upload services and automated media pipelines. Patch exposed systems promptly and restrict untrusted EXR processing where immediate upgrades are impractical. Less-exposed desktop systems should follow through the normal urgent patch cycle.

Technical view

Signed 32-bit arithmetic in internal_exr_undo_piz() can overflow while advancing a PIZ wavelet pointer. The wrapped value causes the next channel to decode from an incorrect address. Because decoding occurs in place, the flaw permits out-of-bounds reads and writes. CVSS 3.1 rates it 8.8 with user interaction required.

Likely exposure

Exposure exists where OpenEXR 3.1.0 through 3.1.13, vulnerable 3.2.x, 3.3.x, or 3.4.x releases process attacker-controlled EXR images. Likely locations include image-upload services, render pipelines, media-processing systems, and applications embedding the library. The bundle does not identify every downstream product.

Exploitation context

Exploitation requires a crafted EXR file to be opened or processed. The supplied bundle marks KEV false, and no cited source reports active exploitation. Out-of-bounds reads and writes create serious confidentiality, integrity, and availability risk, but the provided evidence does not establish reliable code execution.

Researcher notes

The defect combines CWE-190 integer overflow with CWE-125 and CWE-787 memory access violations. nx, ny, and wcount are signed integers whose product can wrap during PIZ decoding. Assessment should focus on reachable PIZ decode paths, bundled library copies, static linking, and downstream packages carrying backports.

Mitigation direction

  • Upgrade 3.2.x deployments to OpenEXR 3.2.7 or later.
  • Upgrade 3.3.x deployments to OpenEXR 3.3.9 or later.
  • Upgrade 3.4.x deployments to OpenEXR 3.4.9 or later.
  • Move affected 3.1.x deployments to a supported fixed release.
  • Restrict processing of untrusted EXR files until upgrades are complete.

Validation and detection

  • Inventory direct and transitive OpenEXR dependencies across applications, containers, workstations, and processing services.
  • Confirm deployed versions fall outside all listed vulnerable ranges.
  • Identify workflows that accept EXR files from external or untrusted sources.
  • Retest EXR decoding and dependent image workflows after upgrading.
  • Review Red Hat advisories for distribution-specific package status and updates.
Prepared
Confidence
high
Sources
6

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.

Open ATT&CK lookup
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.

Open ATT&CK lookup
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.