What is CVE-2026-59186?

CVE-2026-59186 is OpenEXR: Heap out-of-bounds write in TiledRgbaInputFile via integer overflow on 32-bit (ILP32) builds. The supplied enrichment data classifies it as Memory Corruption mapped to CWE-122 Heap-based Buffer Overflow; CWE-190 Integer Overflow or Wraparound; CWE-787 Out-of-bounds Write.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-59186. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-59186 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

A public PoC is not confirmed from current sources for CVE-2026-59186. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-59186 using CVSS 7.1, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

highMemory Corruption

CVE-2026-59186

CVE-2026-59186 — OpenEXR: Heap out-of-bounds write in TiledRgbaInputFile via integer overflow on 32-bit (ILP32) builds

OpenEXR is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. In versions before 3.2.11, 3.3.0 through 3.3.12, and 3.4.0 through 3.4.13, a crafted tiled EXR can trigger a heap out-of-bounds write on 32-bit/ILP32 builds when read through the public TiledRgbaInputFile RGBA API. The file uses a small 40x40 dataWindow but a 65537x65537 tile size. On ILP32, the Array2D<Rgba> tile-conversion buffer size calculation overflows, allocates a much smaller heap buffer, and tile decode writes past that allocation. This issue is fixed in versions 3.2.11, 3.3.13, and 3.4.14.

Published Aug 25, 2026Updated Aug 25, 2026Sources: NVD, AcademySoftwareFoundation (CNA), GitHub, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

ahead of 0% of scored CVEs

Affects

AcademySoftwareFoundation

3 products listed

CVSS base

7.1

high

Remediation

The vendor's own words where we have them.

Upgrade openexr to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
AcademySoftwareFoundation	openexr	< 3.2.11	Vulnerable
AcademySoftwareFoundation	openexr	>= 3.3.0, < 3.3.13	Vulnerable
AcademySoftwareFoundation	openexr	>= 3.4.0, < 3.4.14	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

High

Confidentiality

None

Integrity

Low

Scope

Unchanged

Attack Complexity

Low

Attack Vector

Network

Privileges Req

None

User Interaction

Required

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
7.1	CVSS 3.1	high	2.8	4.2	GitHub (CNA), AcademySoftwareFoundation (CNA)

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

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-122 · Heap-based Buffer Overflow

DoS: Crash, Exit, or Restart
DoS: Resource Consumption (CPU)
DoS: Resource Consumption (Memory)
Execute Unauthorized Code or Commands

Mitigation: Pre-design: Use a language or compiler that performs automatic bounds checking.

CWE-190 · Integer Overflow or Wraparound

DoS: Crash, Exit, or Restart
DoS: Resource Consumption (CPU)
DoS: Resource Consumption (Memory)
DoS: Instability

Mitigation: Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.

Weakness & attack patterns

CWE-122Heap-based Buffer Overflow
CWE-190Integer Overflow or Wraparound
CWE-787Out-of-bounds Write

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-92 · Forced Integer Overflow

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Search application, proxy, and WAF logs for requests touching /ILP32.
Prioritize edge telemetry for network-reachable openexr.

web/proxy/WAF logsapplication logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 7.1 (AV:N)
Aug 25, 2026 · NVD
Initial · CVE published
Aug 25, 2026 · NVD

Source activity

Readings a source repeats on a schedule, counted rather than listed.

2×ModifiedAug 25, 2026 · SOCRadar CTI

References

4 on the record

github.com/AcademySoftwareFoundation/openexr/commit/71907b44ce9a1b05bf3934b8a7821752750731ab
Exploit, Third Party Advisory, Mitre, NIST
github.com/AcademySoftwareFoundation/openexr/commit/904141d3a1f86327ad1e2b93fc92ce2dd5881d34
Exploit, Third Party Advisory, Mitre, NIST
github.com/AcademySoftwareFoundation/openexr/commit/b1a5887372772d79328f4eb42b7f86352a38170b
Exploit, Third Party Advisory, Mitre, NIST
github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-f667-c4wm-c8gq
Exploit, Third Party Advisory, Mitre, NIST

Elsewhere on this site

AcademySoftwareFoundationevery CVE for this vendor
Memory Corruptionsame class
CWE-122other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2026-59186 is OpenEXR: Heap out-of-bounds write in TiledRgbaInputFile via integer overflow on 32-bit (ILP32) builds, a high vulnerability affecting openexr from AcademySoftwareFoundation. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-59186. Public exploit evidence is: A public PoC is not confirmed from current sources for CVE-2026-59186. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 7.1 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.