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NVD / CVE Program· CNA GitHub_M

CVE-2026-55373: OpenEXR: OpenEXRUtil SampleCountChannel endEdit() can loop forever on UINT_MAX sample counts

MediumCVSS 6.2 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 24/100)

  • 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: 0.15% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: openexr (Debian:13) 3.2.12-1~deb13u1; openexr (Debian:14) 3.4.14-0.1; openexr (openSUSE:Leap 16.0) 3.2.2-160000.9.1.

Low priority for now. Upgrade to openexr (Debian:13) 3.2.12-1~deb13u1; openexr (Debian:14) 3.4.14-0.1; openexr (openSUSE:Leap 16.0) 3.2.2-160000.9.1 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 is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. Versions prior to 3.2.10, 3.3.12, and 3.4.13 contain an infinite-loop vulnerability in SampleCountChannel. The helper roundListSizeUp() rounds a sample-list size up to the next power of two using repeated unsigned left shifts, which terminates for normal values but fails for UINT_MAX: the sequence reaches 0x80000000, and the next left shift wraps the 32-bit value to 0. Because 0 remains less than UINT_MAX, the loop never progresses and never exits. The bug is reachable through public OpenEXRUtil APIs, either by editing the sample-count buffer through SampleCountChannel::Edit (whose destructor calls endEdit()) or by calling SampleCountChannel::set(x, y, UINT_MAX) on a valid pixel. This issue has been fixed in versions 3.2.10, 3.3.12, and 3.4.13.

Published
Aug 25, 2026
Updated
Oct 12, 2026
EPSS
0.1% · 4th percentile

Report tools

JSON

Action score

24

Monitor

Low priority for now.

CVSS
24 / 40 · 6.2 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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
6.2
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

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

Follow CVE-2026-55373

When you'll hear from us

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  • 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.

—

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

    • < 3.2.10, >= 3.3.0, < 3.3.12, >= 3.4.0, < 3.4.13affected

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12openexrfrom 0—
Debian:13openexrbefore 3.2.12-1~deb13u13.2.12-1~deb13u1
Debian:14openexrbefore 3.4.14-0.13.4.14-0.1
openSUSE:Leap 16.0openexrbefore 3.2.2-160000.9.13.2.2-160000.9.1
openSUSE:Tumbleweedopenexrbefore 3.4.13-1.13.4.13-1.1
SUSE:Linux Enterprise Module for Desktop Applications 15 SP7openexrbefore 2.2.1-150000.3.52.12.2.1-150000.3.52.1
SUSE:Linux Enterprise Server 16.0openexrbefore 3.2.2-160000.9.13.2.2-160000.9.1

Same product

academysoftwarefoundation: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-68515OpenEXR: Heap out-of-bounds write in exrmultiview with subsampled channel union
    28Monitor
  • CVE-2026-68513OpenEXR: Heap buffer overflow in PyOpenEXR from literal/prefixed RGB channel name collision
    28Monitor
  • CVE-2026-59981OpenEXR: Heap OOB read in SampleCountChannel row when using nonzero dataWindow
    28Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-55059Aug 25, 2026 · OpenEXR: OpenEXRUtil SampleCountChannel row setter heap has an out-of-bounds write vulnerability
    24Monitor
  • ← EarlierCVE-2026-55371Aug 25, 2026 · OpenEXR: OpenEXRCore exr_attr_set_bytes() accepts NULL type_hint with positive hint_length
    27Monitor
  • Later →CVE-2026-59183Aug 25, 2026 · OpenEXR: Signed Integer Overflow Leading to Out-of-Bounds Memory Access in Deep Tile Decoding
    22Monitor

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
debian:openexr3.2.12-1~deb13u1 · Debian:13Package registry (OSV)
debian:openexr3.4.14-0.1 · Debian:14Package registry (OSV)
opensuse:openexr3.4.13-1.1 · openSUSE:TumbleweedPackage registry (OSV)
suse:openexr3.2.2-160000.9.1 · SUSE:Linux Enterprise Server 16.0Package 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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Variant candidates

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

  • CVE-2026-599820 days apartOpenEXR: DWAA InputFile AC buffer overflow on ILP32 platforms
    28Monitor
  • CVE-2026-591830 days apartOpenEXR: Signed Integer Overflow Leading to Out-of-Bounds Memory Access in Deep Tile Decoding
    22Monitor
  • CVE-2026-549200 days apartOpenEXR: Integer overflow and uninitialized pointer cause invalid delete in OpenEXRUtil image resize
    0Monitor

Not on record for this CVE: patch commit or PR link · researcher credit · public bounty program.

Technical details

Attack conditions

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

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-190 · Integer Overflow or Wraparound

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/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.

ATT&CK techniques

—

References

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

All records