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NVD / CVE Program· CNA GitHub_M

CVE-2026-34379: OpenEXR has a misaligned write in LossyDctDecoder_execute leading to undefined behavior (DWA/DWAB decompression)

Noroxi assessment

Priority: Monitor (action score 28/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.29% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: AcademySoftwareFoundation openexr 3.2.7.

Low priority for now. Upgrade to AcademySoftwareFoundation openexr 3.2.7 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.2.0 to before 3.2.7, 3.3.9, and 3.4.9, a misaligned memory write vulnerability exists in LossyDctDecoder_execute() in src/lib/OpenEXRCore/internal_dwa_decoder.h:749. When decoding a DWA or DWAB-compressed EXR file containing a FLOAT-type channel, the decoder performs an in-place HALF→FLOAT conversion by casting an unaligned uint8_t * row pointer to float * and writing through it. Because the row buffer may not be 4-byte aligned, this constitutes undefined behavior under the C standard and crashes immediately on architectures that enforce alignment (ARM, RISC-V, etc.). On x86 it is silently tolerated at runtime but remains exploitable via compiler optimizations that assume aligned access. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9.

HighCVSS 7.1 · v3.1—No exploit Fix available
Published
Apr 6, 2026
Updated
Oct 26, 2026
EPSS
0.2% · 22th percentile

Report tools

JSON

Action score

28

Monitor

Low priority for now.

CVSS
28 / 40 · 7.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
7.1
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
openexropenexr

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • openexr openexr3.2.0 and later · before 3.2.7
  • openexr openexr3.3.0 and later · before 3.3.9
  • openexr openexr3.4.0 and later · before 3.4.9

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • AcademySoftwareFoundation openexr

    • >= 3.2.0, < 3.2.7, >= 3.3.0, < 3.3.9, >= 3.4.0, < 3.4.9affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.22openexrfrom 3.2.0 · before 3.3.11-r03.3.11-r0
Alpine:v3.23openexrfrom 3.2.0 · before 3.4.13-r03.4.13-r0
Alpine:v3.24openexrfrom 3.2.0 · before 3.4.10-r03.4.10-r0
Debian:12openexrfrom 0—
Debian:14openexrbefore 3.4.14-0.13.4.14-0.1
openSUSE:Leap 16.0openexrbefore 3.2.2-160000.6.13.2.2-160000.6.1
openSUSE:Tumbleweedopenexrbefore 3.4.9-1.13.4.9-1.1

Same product

openexr: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-5841OpenEXR Heap Overflow in Scanline Deep Data Parsing
    36Monitor
  • CVE-2021-23169A heap-buffer overflow was found in the copyIntoFrameBuffer function of OpenEXR in versions before 3.0.1.
    36Monitor
  • CVE-2017-9115In OpenEXR 2.2.0, an invalid write of size 2 in the = operator function in half.h could cause the application to crash or execute arbitrary…
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-34545Apr 1, 2026 · OpenEXR: integer overflow lead to OOB in HTJ2K decoder
    33Monitor
  • ← EarlierCVE-2026-34378Apr 6, 2026 · OpenEXR has a signed integer overflow in generic_unpack() when parsing EXR files with crafted negative dataWindow.min.x
    26Monitor
  • Later →CVE-2026-34380Apr 6, 2026 · OpenEXR has a signed integer overflow (undefined behavior) in undo_pxr24_impl may allow bounds-check bypass in PXR24 decompression
    23Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
AcademySoftwareFoundation openexr3.2.7 · descriptionVendor (CNA)
alpine:openexr3.3.11-r0 · Alpine:v3.22Package registry (OSV)
debian:openexr3.4.14-0.1 · Debian:14Package registry (OSV)
opensuse:openexr3.4.9-1.1 · openSUSE:TumbleweedPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
low · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
None
Integrity impact
Low
Availability impact
High

Weakness class (CWE)

CWE-704 · Incorrect Type Conversion or Cast

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records