CyberSecBulletin
CVE-2026-53532NVD status: Deferred

openexr: Reachable Assertion

Published Updated By the CyberSecBulletin desk

CVE-2026-53532 is a high-severity reachable assertion vulnerability in openexr from AcademySoftwareFoundation, with a CVSS 4.0 base score of 7.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected openexr versions: >= 3.4.0, < 3.4.13. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.45% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of openexr you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  4. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
AcademySoftwareFoundationopenexr>= 3.4.0, < 3.4.13Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
NoneNo account or login is needed.
User interaction
PassiveA user only needs to do something routine, such as viewing a page.
Confidentiality (vulnerable system)
NoneNo loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
NoneNo loss of integrity on the vulnerable system.
Availability (vulnerable system)
HighSerious loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/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. Scored by CNA (github.com).

Official description

OpenEXR is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. In versions 3.4.0 through 3.4.12, a crafted HTJ2K-compressed EXR file causes an unconditional process abort in any application that calls exr_start_read() on untrusted input, resulting in denial of service. The crash is triggered by a QCD marker whose lower five bits are zero, which OpenEXR passes into the vendored OpenJPH library while constructing the codestream and evaluating its quantization delta parameters. OpenJPH uses an assertion rather than a recoverable error to validate those bits, so any invalid value calls abort() directly and cannot be intercepted by surrounding error handling, a problem compounded by OpenEXR wrapping only its internal HT header parser in error handling while leaving the later codestream read and construction calls unprotected. This issue has been resolved in version 3.4.13.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Reachable Assertion

The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.

How developers prevent this class of flaw

  • If the assertion statement is required (e.g., for security or reliability), change the invoking code to avoid the conditions that trigger the assertion.
  • Consider changing the assertion to some other less fatal error. This might not be easy to implement, since other code may be needed to handle the error.
  • Make sensitive open/close operations non-reachable from directly user-controlled data (e.g. open/close resources)

More Reachable Assertion vulnerabilities (CWE-617)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in openexr

All openexr vulnerabilities

Recent Reachable Assertion vulnerabilities

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