CVE-2026-42216 | OpenEXR: Out-of-bounds read in `IDManifest::init()` during prefix expansion

Exp

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From versions 3.0.0 to before 3.2.9, 3.3.0 to before 3.3.11, and 3.4.0 to before 3.4.11, IDManifest::init() reconstructs strings from a prefix-compressed representation. If the previous string is longer than 255 bytes, the next string is expected to begin with a 2-byte prefix length. The code reads stringList[i][0] and stringList[i][1] without checking that the current string has at least two bytes. This issue has been patched in versions 3.2.9, 3.3.11, and 3.4.11.

Published: 2026-05-07 Last update: 2026-05-08 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-42216 is rated Exploit Available (56.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.06%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-42216

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-42216

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-13 0.04% 0.06% +0.02%
2 2026-05-07 — 0.04% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-42216

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 4.0 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/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 Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:H)
High confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:N)
No integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:H)
High availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:X)
Not defined: no reliable threat intelligence; scoring assumes the worst case (equivalent to Attacked).
Confidentiality requirement (CR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X)
Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X)
Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X)
Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X)
Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X)
Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X)
Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X)
Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X)
Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X)
Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X)
Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X)
Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X)
Not evaluated.
Automatable (supplemental) (AU:X)
Not evaluated.
Recovery (supplemental) (R:X)
Not evaluated.
Value density (supplemental) (V:X)
Not evaluated.
Vulnerability response effort (supplemental) (RE:X)
Not evaluated.
Provider urgency (supplemental) (U:X)
Not evaluated.
 — — [email protected]
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.2 [email protected]

Weakness enumeration for CVE-2026-42216

OS Trackers for CVE-2026-42216

vendor priority summary link
debian not yet assigned CVE-2026-42216 not yet assigned priority: Debian including 1 source packages (openexr), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2026-42216
suse high — https://www.suse.com/security/cve/CVE-2026-42216/
ubuntu medium CVE-2026-42216 medium priority: Ubuntu including 1 source packages (openexr), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, resolute, upstream, xenial): needs-triage 8. https://ubuntu.com/security/CVE-2026-42216

Affected software / configurations for CVE-2026-42216

Vendor Product Version Raw CPE
openexr openexr >= 3.0.0, < 3.2.9 cpe:2.3:a:openexr:openexr:*:*:*:*:*:*:*:*
openexr openexr >= 3.3.0, < 3.3.11 cpe:2.3:a:openexr:openexr:*:*:*:*:*:*:*:*
openexr openexr >= 3.4.0, < 3.4.11 cpe:2.3:a:openexr:openexr:*:*:*:*:*:*:*:*

References for CVE-2026-42216

cvelogic Threat Intelligence