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NVD / CVE Program· CNA GitHub_M

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

Noroxi assessment

Priority: Monitor (action score 33/100)

  • 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: 0.63% (FIRST EPSS); higher than 50.3% of all records.
  • Someone with local access to the system can trigger it. No account or password is required. No special conditions are required; it is repeatable.
  • Fixed version: AcademySoftwareFoundation openexr 3.4.7.

Low priority for now. Upgrade to AcademySoftwareFoundation openexr 3.4.7 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 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 8.4 · v4.0—No exploit Fix available
Published
Apr 1, 2026
Updated
Oct 26, 2026
EPSS
0.6% · 50th percentile

Report tools

JSON

Action score

33

Monitor

Low priority for now.

CVSS
33 / 40 · 8.4 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
8.4
NVD has not scored this yet; the score shown is the CNA’s.

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

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

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-34545

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 openexr3.4.0 and later · before 3.4.7

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

    • >= 3.4.0, < 3.4.7affected

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12openexrfrom 0—
Debian:14openexrbefore 3.4.14-0.13.4.14-0.1
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-2026-34543Apr 1, 2026 · OpenEXR: Heap information disclosure in PXR24 decompression via unchecked decompressed size (undo_pxr24_impl)
    34Monitor
  • ← EarlierCVE-2026-34544Apr 1, 2026 · OpenEXR: integer overflow to OOB write in uncompress_b44_impl()
    33Monitor
  • Later →CVE-2026-34378Apr 6, 2026 · OpenEXR has a signed integer overflow in generic_unpack() when parsing EXR files with crafted negative dataWindow.min.x
    26Monitor

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 openexr3.4.7 · descriptionVendor (CNA)
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.

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.

  • CVE-2026-4569678 days apartOpenEXR HTJ2K decoder heap buffer over-read in ht_undo_impl() (DoS)
    33Monitor
  • CVE-2025-48071244 days apartOpenEXR's Forged Unpacked Size can Lead to Heap-Based Buffer Overflow in Deep Scanline Parsing
    33Monitor
  • CVE-2025-1249599 days apartAcademy Software Foundation OpenEXR EXR File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability
    31Monitor
  • CVE-2025-1283999 days apartAcademy Software Foundation OpenEXR EXR File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability
    31Monitor
  • CVE-2025-1284099 days apartAcademy Software Foundation OpenEXR EXR File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability
    31Monitor

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

  • Someone with local access to the system can trigger it.
  • No account or password is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
A
Scope
X

Weakness class (CWE)

CWE-122 · Heap-based Buffer Overflow

CVSS 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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References

Show all references (4 more)

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

All records