● High · CVSS 8.4

How to Fix CVE-2026-27622: Out-of-bounds write in openexr

Q: What is the CVSS score for CVE-2026-27622?

8.4 (High). 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`.

Q: Where is the official advisory for CVE-2026-27622?

The vendor advisory is at [https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-cr4v-6jm6-4963](https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-cr4v-6jm6-4963). The NVD record is at https://nvd.nist.gov/vuln/detail/CVE-2026-27622.

By Sai Kiran Pandrala. Last verified: 2026-05-25.

CVE-2026-27622 is a out-of-bounds write in AcademySoftwareFoundation openexr. The fix is to apply the vendor patch noted below.

⚡ At a glance


Severity	8.4 (High)
Actively exploited?	No public listing in CISA KEV
Affected	openexr >= 2.3.0, < 3.2.6; openexr >= 3.3.0, < 3.3.8; openexr >= 3.4.0, < 3.4.6
Fixed in	See vendor advisory
Type (CWE)	CWE-787: Out-of-bounds Write

What is CVE-2026-27622?

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. In CompositeDeepScanLine::readPixels, per-pixel totals are accumulated in vector<unsigned int> total_sizes for attacker-controlled large counts across many parts, total_sizes[ptr] wraps modulo 2^32. overall_sample_count is then derived from wrapped totals and used in samples[channel].resize(overall_sample_count). Decode pointer setup/consumption proceeds with true sample counts, and write operations in core unpack (generic_unpack_deep_pointers) overrun the undersized composite sample buffer. This vulnerability is fixed in v3.2.6, v3.3.8, and v3.4.6. The CVSS base score is 8.4 (High), which puts this in the upper risk band and warrants a fast patch cycle. The official advisory is at https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-cr4v-6jm6-4963.

Am I affected?

Check the version of openexr you are running and compare it against the Affected row above (openexr >= 2.3.0, < 3.2.6; openexr >= 3.3.0, < 3.3.8; openexr >= 3.4.0, < 3.4.6). If your build sits inside the affected range, you must patch.

Run the version check that fits your platform:


# Linux package check
dpkg -s openexr 2>/dev/null | grep -i ^Version
rpm -q openexr 2>/dev/null
command -v openexr >/dev/null && openexr --version 2>/dev/null


# Windows (PowerShell)
Get-Package -Name "*openexr*" -ErrorAction SilentlyContinue | Select-Object Name, Version
winget list --name "openexr" 2>$null

How to fix CVE-2026-27622

Upgrade openexr to a patched build: See vendor advisory. The vendor advisory is the source of truth for the exact fixed version.

Ubuntu / Debian


sudo apt-get update
sudo apt-get install --only-upgrade openexr
dpkg -s openexr | grep -i ^Version

RHEL / CentOS / Rocky / AlmaLinux


sudo dnf upgrade --refresh openexr -y
# or for older releases:
sudo yum update openexr -y
rpm -q openexr

SUSE / openSUSE


sudo zypper refresh
sudo zypper update openexr
rpm -q openexr

Node.js / npm


# Update the affected package in your project
npm install openexr@latest
npm ls openexr
npm audit fix

Complete PowerShell remediation script (Windows)


# Fix script for CVE-2026-27622 affecting openexr
# Run as administrator. Detect -> backup -> upgrade -> verify -> log.

$ErrorActionPreference = "Stop"
$LogPath  = "C:\Logs\CVE-2026-27622-fix-$(Get-Date -Format yyyyMMdd-HHmmss).log"
New-Item -ItemType Directory -Force (Split-Path $LogPath) | Out-Null
Start-Transcript -Path $LogPath -Append

try {
    Write-Host "[1/4] Detect installed version"
    $pkg = Get-Package -Name "*openexr*" -ErrorAction SilentlyContinue
    if ($pkg) { $pkg | Format-Table Name, Version }
    else { Write-Host "Not detected via Get-Package; try winget list" }

    Write-Host "[2/4] Backup configuration"
    $backup = "C:\Backup\openexr-$(Get-Date -Format yyyyMMdd)"
    New-Item -ItemType Directory -Force $backup | Out-Null
    Get-ChildItem "C:\ProgramData\openexr" -ErrorAction SilentlyContinue |
        Copy-Item -Destination $backup -Recurse -Force -ErrorAction SilentlyContinue

    Write-Host "[3/4] Apply the upgrade to See vendor advisory"
    winget upgrade --name "openexr" --silent --accept-source-agreements --accept-package-agreements
    if ($LASTEXITCODE -ne 0) {
        # Fallback: pull latest via OS update channel
        Install-Module -Name PSWindowsUpdate -Force -SkipPublisherCheck -ErrorAction SilentlyContinue
        Import-Module PSWindowsUpdate
        Install-WindowsUpdate -MicrosoftUpdate -AcceptAll -IgnoreReboot
    }

    Write-Host "[4/4] Verify the patched build"
    winget list --name "openexr"
    Write-Host "Patch applied. Reboot if prompted."
    exit 0
} catch {
    Write-Error "Patch failed: $_"
    exit 1
} finally {
    Stop-Transcript
}

Complete Bash remediation script (Linux)


#!/usr/bin/env bash
# Fix script for CVE-2026-27622 affecting openexr
# Detect -> backup -> upgrade -> verify -> log.

set -euo pipefail
LOG="/var/log/cve-2026-27622-fix-$(date +%Y%m%d-%H%M%S).log"
exec > >(tee -a "$LOG") 2>&1

echo "[1/4] Detect installed version"
if command -v dpkg >/dev/null; then
    dpkg -s openexr 2>/dev/null | grep -i ^Version || echo "openexr not installed via dpkg"
elif command -v rpm >/dev/null; then
    rpm -q openexr || echo "openexr not installed via rpm"
fi

echo "[2/4] Backup configuration"
BACKUP="/root/backup-cve-2026-27622-$(date +%Y%m%d)"
mkdir -p "$BACKUP"
for d in /etc/openexr /etc/openexr.d /etc/openexr.conf; do
    [ -e "$d" ] && cp -a "$d" "$BACKUP/" || true
done

echo "[3/4] Apply the upgrade (target: See vendor advisory)"
if command -v apt-get >/dev/null; then
    apt-get update
    apt-get install --only-upgrade -y openexr
elif command -v dnf >/dev/null; then
    dnf upgrade --refresh -y openexr
elif command -v yum >/dev/null; then
    yum update -y openexr
elif command -v zypper >/dev/null; then
    zypper --non-interactive update openexr
fi

echo "[4/4] Verify the patched build"
if command -v dpkg >/dev/null; then
    dpkg -s openexr 2>/dev/null | grep -i ^Version
elif command -v rpm >/dev/null; then
    rpm -q openexr
fi
echo "Done. Restart any service that loaded the old library."

If you can't patch immediately

Apply at least one of the following inline controls until you can deploy the patched build. None replace the upgrade.

Restrict exposure with nftables (Linux)


# Allow only trusted CIDR to reach the affected service ports
sudo nft add table inet filter 2>/dev/null || true
sudo nft 'add chain inet filter input { type filter hook input priority 0 ; }' 2>/dev/null || true
sudo nft 'add rule inet filter input tcp dport {80, 443} ip saddr != 10.0.0.0/8 drop'
sudo nft list ruleset

Block at the host firewall (Windows)


New-NetFirewallRule -DisplayName "Block-CVE-2026-27622" -Direction Inbound -Action Block -Protocol TCP -LocalPort 80,443 -RemoteAddress Any -Enabled True
Get-NetFirewallRule -DisplayName "Block-CVE-2026-27622"

Disable the affected service (Linux)


sudo systemctl stop openexr 2>/dev/null || true
sudo systemctl disable openexr 2>/dev/null || true

If the vendor advisory lists an official workaround, prefer that wording verbatim. If no workaround is published, the only safe remediation is the patch.

How to verify the fix worked

After upgrading, confirm the installed version matches the patched build and that no old library is still loaded by a long-running process.


# Linux
dpkg -s openexr 2>/dev/null | grep -i ^Version
rpm -q openexr 2>/dev/null || true
# Pid map check for old library handles
sudo lsof +c0 2>/dev/null | grep -i "DEL.*lib" || true


# Windows
Get-Package -Name "*openexr*" | Select-Object Name, Version
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 5

Expected: the reported version is at or above See vendor advisory. Restart the affected service (systemctl restart <service> on Linux, or restart the Windows service) so it loads the patched binary.

Frequently asked questions

Other vulnerabilities in the same area that are worth patching alongside this one:

How to Fix CVE-2026-24830: Critical Vulnerability in IronOS — Critical Vulnerability in IronOS
How to Fix CVE-2026-34740: AVideo (Bundle Sibling) — AVideo (Bundle Sibling)
How to Fix CVE-2026-26931: CWE-789 Memory Allocation with Excessive Size Value in Metricbeat , CWE-789 Memory Allocation with Excessive Size Value in Metricbeat
How to Fix CVE-2026-26263: glpi (Bundle Sibling) , glpi (Bundle Sibling)
How to Fix CVE-2026-7510: Authorization Bypass in DefectDojo , Authorization Bypass in DefectDojo

Is CVE-2026-27622 actively exploited?

There is no public confirmation of exploitation in the wild listed in CISA KEV at the time of this writing. Patch anyway. Public exploits commonly follow disclosure within weeks.

Do I need to reboot after patching CVE-2026-27622?

For kernel and OS-level updates, yes. For most userland packages a systemctl restart <service> is enough on Linux, and restarting the Windows service or app on Windows. Any process that loaded the old library keeps using it until restarted.

What is the CVSS score for CVE-2026-27622?

8.4 (High). 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.

Where is the official advisory for CVE-2026-27622?

The vendor advisory is at https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-cr4v-6jm6-4963. The NVD record is at https://nvd.nist.gov/vuln/detail/CVE-2026-27622.

References

Official vendor advisory: https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-cr4v-6jm6-4963
NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-27622
CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

*Written by Sai Kiran Pandrala. Assembled from the official vendor advisory, NVD record, and CISA KEV listing on 2026-05-25. Always confirm against the vendor's advisory before applying changes in production.*