CVE-2026-10305: Samsung rlottie Buffer Overflow Flaw

CVE-2026-10305 Overview

CVE-2026-10305 is an out-of-bounds read vulnerability [CWE-125] in Samsung's open source rlottie library. The library renders Lottie animations and is widely embedded in mobile, desktop, and embedded applications. The flaw allows an attacker-supplied animation file to trigger a buffer overread during parsing or rendering. The issue affects all rlottie versions prior to commit 223a2a41ba4f462e4abe767bebba49a366c9b9fd.

Exploitation requires local access and user interaction, such as opening a crafted Lottie file. Successful exploitation can disclose adjacent memory contents or cause the host application to crash.

Critical Impact

An attacker can deliver a malicious Lottie animation file that triggers an out-of-bounds read in rlottie, leading to high availability impact and limited information disclosure in any application embedding the library.

Affected Products

• Samsung rlottie (open source animation rendering library)
• All commits prior to 223a2a41ba4f462e4abe767bebba49a366c9b9fd
• Downstream applications and platforms embedding vulnerable rlottie builds

Discovery Timeline

• 2026-06-04 - CVE-2026-10305 published to NVD
• 2026-06-04 - Last updated in NVD database

Technical Details for CVE-2026-10305

Vulnerability Analysis

The vulnerability is an out-of-bounds read [CWE-125] in the rlottie parsing or rendering pipeline. rlottie consumes JSON-based Lottie animation data and produces rasterized frames. When the library processes a malformed or maliciously crafted animation, it reads memory beyond the bounds of an intended buffer.

The attack requires local access and user interaction. An attacker convinces a user to load a crafted Lottie file in an application that embeds rlottie. The CVSS vector indicates no confidentiality impact, low integrity impact, and high availability impact. Process crashes are the most likely outcome, though adjacent memory contents may be exposed through rendered output or error paths.

The fix is delivered as upstream commit 223a2a41ba4f462e4abe767bebba49a366c9b9fd, merged through GitHub Pull Request #587.

Root Cause

The root cause is missing or insufficient bounds checking when accessing buffers populated from untrusted Lottie animation data. Parser routines trust attacker-controlled indices, offsets, or counts and dereference memory past the allocated region. The patched commit adds the boundary validation needed to constrain reads within allocated buffers.

Attack Vector

The attack vector is local with required user interaction. An attacker crafts a Lottie JSON file containing manipulated structural fields that drive the parser past buffer limits. The user opens the file in any application that links a vulnerable rlottie build. The malformed input triggers the overread during parsing or frame rendering. Refer to the upstream pull request for the technical fix details.

Detection Methods for CVE-2026-10305

Indicators of Compromise

• Repeated crashes or abnormal terminations of applications that render Lottie animations
• Lottie JSON files from untrusted sources with malformed shape, layer, or keyframe structures
• AddressSanitizer or crash telemetry reporting heap-buffer-overflow READ events inside rlottie symbols

Detection Strategies

• Inventory applications and SDKs that statically or dynamically link rlottie and compare against commit 223a2a41ba4f462e4abe767bebba49a366c9b9fd
• Enable AddressSanitizer or equivalent memory error detectors in development and QA builds that load Lottie content
• Inspect crash dumps for faulting addresses inside rlottie parsing functions when handling animation assets

Monitoring Recommendations

• Forward application crash telemetry from endpoints to a centralized analytics pipeline for triage
• Alert on clusters of crashes tied to processes that load Lottie animations from email, chat, or web downloads
• Track introduction of Lottie files into shared file stores and code repositories for review

How to Mitigate CVE-2026-10305

Immediate Actions Required

• Update rlottie to a build that includes commit 223a2a41ba4f462e4abe767bebba49a366c9b9fd or later
• Rebuild and redeploy all downstream applications and SDKs that statically link rlottie
• Restrict ingestion of Lottie animation files from untrusted senders until patched builds are deployed

Patch Information

The fix is available upstream in the Samsung rlottie repository through GitHub Pull Request #587. Integrators must pull commit 223a2a41ba4f462e4abe767bebba49a366c9b9fd or a later revision and rebuild dependent binaries. Package maintainers should publish updated versions for distributions that ship rlottie.

Workarounds

• Block or quarantine Lottie JSON files received from external or untrusted sources at email and web gateways
• Disable in-app Lottie rendering features in high-risk workflows until updated binaries are deployed
• Run applications that render Lottie content under sandboxing or least-privilege execution contexts to limit crash impact

# Verify the rlottie commit included in a source checkout
cd rlottie
git log --oneline | grep 223a2a41ba4f462e4abe767bebba49a366c9b9fd

# Update to the patched revision
git fetch origin
git checkout 223a2a41ba4f462e4abe767bebba49a366c9b9fd