CVE-2026-39886: CWE-190: Integer Overflow or Wraparound in AcademySoftwareFoundation openexr
OpenEXR versions 3. 4. 0 through 3. 4. 9 contain a signed integer overflow vulnerability in the HTJ2K decompression path. The vulnerability occurs in the ht_undo_impl() function where a 32-bit signed integer accumulator for bytes-per-line (bpl) can overflow when processing a specially crafted EXR file with a large number of FLOAT channels and maximum width. This overflow can lead to undefined behavior and potentially a heap out-of-bounds write on hosts that allow large memory allocations. Version 3. 4. 10 includes a fix for this issue.
AI Analysis
Technical Summary
The vulnerability CVE-2026-39886 affects OpenEXR versions 3.4.0 to 3.4.9 in the HTJ2K decompression code. Specifically, the ht_undo_impl() function uses a 32-bit signed integer to accumulate bytes-per-line (bpl) without overflow protection. When processing an EXR file crafted with 16,385 FLOAT channels at the maximum width of 32,767, this accumulator overflows INT_MAX, causing undefined behavior confirmed by UBSan. On systems where a large (~64 GB) allocation succeeds, the overflowed negative bpl value is used as a pointer advance, leading to a heap out-of-bounds write. On memory-constrained systems, the allocation fails before the vulnerable code is reached. This is a distinct overflow from a previously fixed issue in the same function. The fix for this vulnerability is included in OpenEXR version 3.4.10.
Potential Impact
The vulnerability can cause a heap out-of-bounds write, which may lead to application crashes or denial of service. There is no indication of confidentiality or integrity impact. Exploitation requires a crafted EXR file with extreme parameters and a permissive memory allocator environment. No known exploits are reported in the wild.
Mitigation Recommendations
A fix for this vulnerability is available in OpenEXR version 3.4.10. Users should upgrade to version 3.4.10 or later to remediate this issue. Patch status is not explicitly stated beyond the version containing the fix; therefore, verify with the vendor advisory for the latest remediation guidance.
CVE-2026-39886: CWE-190: Integer Overflow or Wraparound in AcademySoftwareFoundation openexr
Description
OpenEXR versions 3. 4. 0 through 3. 4. 9 contain a signed integer overflow vulnerability in the HTJ2K decompression path. The vulnerability occurs in the ht_undo_impl() function where a 32-bit signed integer accumulator for bytes-per-line (bpl) can overflow when processing a specially crafted EXR file with a large number of FLOAT channels and maximum width. This overflow can lead to undefined behavior and potentially a heap out-of-bounds write on hosts that allow large memory allocations. Version 3. 4. 10 includes a fix for this issue.
CVSS v3.1
Score 5.3medium
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-39886 affects OpenEXR versions 3.4.0 to 3.4.9 in the HTJ2K decompression code. Specifically, the ht_undo_impl() function uses a 32-bit signed integer to accumulate bytes-per-line (bpl) without overflow protection. When processing an EXR file crafted with 16,385 FLOAT channels at the maximum width of 32,767, this accumulator overflows INT_MAX, causing undefined behavior confirmed by UBSan. On systems where a large (~64 GB) allocation succeeds, the overflowed negative bpl value is used as a pointer advance, leading to a heap out-of-bounds write. On memory-constrained systems, the allocation fails before the vulnerable code is reached. This is a distinct overflow from a previously fixed issue in the same function. The fix for this vulnerability is included in OpenEXR version 3.4.10.
Potential Impact
The vulnerability can cause a heap out-of-bounds write, which may lead to application crashes or denial of service. There is no indication of confidentiality or integrity impact. Exploitation requires a crafted EXR file with extreme parameters and a permissive memory allocator environment. No known exploits are reported in the wild.
Mitigation Recommendations
A fix for this vulnerability is available in OpenEXR version 3.4.10. Users should upgrade to version 3.4.10 or later to remediate this issue. Patch status is not explicitly stated beyond the version containing the fix; therefore, verify with the vendor advisory for the latest remediation guidance.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-07T20:32:03.011Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69e6d6dd19fe3cd2cd64f723
Added to database: 4/21/2026, 1:46:05 AM
Last enriched: 4/28/2026, 6:05:57 AM
Last updated: 6/5/2026, 7:07:55 AM
Views: 68
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