CVE-2026-21045: libimagecodec Buffer Overflow Vulnerability

CVE-2026-21045 Overview

CVE-2026-21045 is an out-of-bounds write vulnerability in libimagecodec.media.quram.so, a shared library used by Samsung Mobile devices to parse image formats. The flaw resides in the Tagged Image File Format (TIFF) parsing routine and allows remote attackers to write memory outside allocated buffer boundaries. The issue affects Samsung Mobile builds prior to the Security Maintenance Release (SMR) Jul-2026 Release 1. Because TIFF parsing can be triggered by processing untrusted image content, the vulnerability is reachable over the network without authentication or user interaction.

Critical Impact
Remote attackers can corrupt memory in the media parsing library, creating a path toward code execution or targeted integrity compromise on affected Samsung Mobile devices.

Affected Products

Samsung Mobile devices running builds prior to SMR Jul-2026 Release 1
libimagecodec.media.quram.so shared library (TIFF parser)
Samsung media framework components that dispatch TIFF content to the Quram image codec

Discovery Timeline

2026-07-10 - CVE-2026-21045 published to the National Vulnerability Database
2026-07-10 - Last updated in the NVD database
July 2026 - Samsung addresses the issue in the Samsung Mobile Security Update for SMR Jul-2026 Release 1

Technical Details for CVE-2026-21045

Vulnerability Analysis

The vulnerability is an out-of-bounds write [CWE-787] in the TIFF parsing logic of libimagecodec.media.quram.so. The library, developed by Quram and bundled by Samsung, decodes image formats consumed by the Android media framework, messaging apps, gallery previews, and other system surfaces. When the parser processes a malformed TIFF structure, it writes data past the boundaries of an allocated buffer. That write corrupts adjacent heap memory used by the media process. An attacker who controls the TIFF payload can influence the corruption to overwrite function pointers, object metadata, or codec state. The primary security impact identified in the advisory is on integrity, with a secondary availability impact from process crashes during exploitation attempts.

Root Cause

The parser fails to correctly validate size, offset, or count fields extracted from TIFF Image File Directory (IFD) entries before using them to index into or copy data into a fixed destination buffer. Malicious tag values cause the codec to compute a write beyond the allocated region.

Attack Vector

Exploitation is remote. An attacker delivers a crafted TIFF image through any channel that causes the media framework to invoke the Quram codec, including multimedia messaging, email attachments, browser-rendered content, or thumbnail generation from received files. The CVSS 4.0 metrics indicate the attack requires no privileges and no user interaction, though a passive attack requirement (AT:P) is set, meaning specific conditions in the parser state must be met.

No verified proof-of-concept code is publicly available. See the Samsung Mobile Security Update for vendor technical details.

Detection Methods for CVE-2026-21045

Indicators of Compromise

Unexpected crashes or tombstone files referencing libimagecodec.media.quram.so in the media server process
Delivery of TIFF (.tif, .tiff) attachments through MMS, RCS, or email to unpatched Samsung devices
Media framework processes spawning atypical child processes or writing to unusual filesystem locations after image rendering

Detection Strategies

Inspect mobile device management (MDM) telemetry for Samsung devices reporting build fingerprints older than SMR Jul-2026 Release 1
Filter inbound messaging and email gateways for TIFF payloads with malformed IFD entries or anomalous tag counts
Correlate media process crash signals with recent inbound image delivery events

Monitoring Recommendations

Enable and centralize Android logcat and tombstoned collection for fleet Samsung devices
Track patch level (ro.build.version.security_patch) across the mobile fleet and alert on devices lagging the July 2026 SMR
Monitor messaging gateways for a spike in TIFF attachments targeting Samsung device user agents

How to Mitigate CVE-2026-21045

Immediate Actions Required

Apply the Samsung SMR Jul-2026 Release 1 update on all affected devices through Settings → Software Update
Restrict automatic download of MMS attachments in the default messaging application until devices are patched
Advise users to avoid opening TIFF images from untrusted sources on unpatched Samsung devices

Patch Information

Samsung addressed CVE-2026-21045 in the Security Maintenance Release for July 2026 (SMR Jul-2026 Release 1). Details and per-model rollout are published in the Samsung Mobile Security Update bulletin. Devices should report a security patch level of July 2026 or later after installation.

Workarounds

Disable auto-retrieval of MMS messages in the messaging app to block automatic TIFF parsing
Block or strip TIFF attachments at the email gateway for accounts synced to unpatched devices
Use enterprise mobility management policies to enforce minimum security patch levels before granting corporate resource access

bash

# Verify current Samsung security patch level via adb
adb shell getprop ro.build.version.security_patch
# Expected value on patched devices: 2026-07-01 or later