CVE-2026-40492 | HappySeaFox sail XWD Codec pixmap_depth out-of-bounds write (GHSA-526v-vm72-4v64)

VDB-358162 · CVE-2026-40492 · GHSA-526V-VM72-4V64 HAPPYSEAFOX SAIL XWD CODEC PIXMAP_DEPTH OUT-OF-BOUNDS WRITE HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 8.4 $0-$5k 1.91+ Summaryinfo A vulnerability classified as critical was found in HappySeaFox sail. This affects the function pixmap_depth of the component XWD Codec. Executing a manipulation can lead to out-of-bounds write. This vulnerability is tracked as CVE-2026-40492. The attack can be launched remotely. No exploit exists. A patch should be applied to remediate this issue. Detailsinfo A vulnerability was found in HappySeaFox sail (version unknown). It has been declared as critical. This vulnerability affects the function pixmap_depth of the component XWD Codec. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes: SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. Prior to commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02, the XWD codec resolves pixel format based on `pixmap_depth` but the byte-swap code uses `bits_per_pixel` independently. When `pixmap_depth=8` (BPP8_INDEXED, 1 byte/pixel buffer) but `bits_per_pixel=32`, the byte-swap loop accesses memory as `uint32_t*`, reading/writing 4x the allocated buffer size. This is a different vulnerability from the previously reported GHSA-3g38-x2pj-mv55 (CVE-2026-27168), which addressed `bytes_per_line` validation. Commit 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02 contains a patch. The advisory is available at github.com. This vulnerability was named CVE-2026-40492 since 04/13/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit. Applying the patch 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02 is able to eliminate this problem. The bugfix is ready for download at github.com. Productinfo Vendor HappySeaFox Name sail License open-source Website Product: https://github.com/HappySeaFox/sail/ CPE 2.3info 🔒 CPE 2.2info 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 8.5 VulDB Meta Temp Score: 8.4 VulDB Base Score: 7.3 VulDB Temp Score: 7.0 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 9.8 CNA Vector (GitHub_M): 🔒 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Out-of-bounds write CWE: CWE-787 / CWE-119 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Patch Status: 🔍 0-Day Time: 🔒 Patch: 36aa5c7ec8a2bb35f6fb867a1177a6f141156b02 Timelineinfo 04/13/2026 CVE reserved 04/18/2026 +5 days Advisory disclosed 04/18/2026 +0 days VulDB entry created 04/18/2026 +0 days VulDB entry last update Sourcesinfo Product: github.com Advisory: GHSA-526v-vm72-4v64 Status: Confirmed CVE: CVE-2026-40492 (🔒) GCVE (CVE): GCVE-0-2026-40492 GCVE (VulDB): GCVE-100-358162 Entryinfo Created: 04/18/2026 09:01 Changes: 04/18/2026 09:01 (66) Complete: 🔍 Cache ID: 99:EE0:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸