CVE-2026-19588: Samsung rlottie Buffer Overflow Flaw

CVE-2026-19588 Overview

CVE-2026-19588 is an integer overflow leading to a buffer overflow in Samsung's open source rlottie library. The rlottie library renders Lottie animations, which are JSON-based vector animations widely embedded in mobile apps, desktop clients, and web components. An attacker can craft a malicious animation file that triggers arithmetic overflow during size calculations, causing subsequent buffer allocations or writes to exceed intended bounds. Successful exploitation results in an application crash and denial of service. The flaw is tracked under CWE-680: Integer Overflow to Buffer Overflow and requires user interaction to open or process the crafted content.

Critical Impact
Remote attackers can trigger high-impact availability loss in applications that parse untrusted Lottie animation files.

Affected Products

Samsung Open Source rlottie library
Applications embedding rlottie for Lottie animation rendering
Downstream projects consuming vulnerable rlottie builds

Discovery Timeline

2026-08-12 - CVE-2026-19588 published to NVD
2026-08-12 - Last updated in NVD database

Technical Details for CVE-2026-19588

Vulnerability Analysis

The vulnerability resides in size or count calculations performed by rlottie when parsing Lottie animation data. Attacker-controlled numeric fields feed into arithmetic operations that wrap past the maximum integer value. The wrapped result produces an undersized allocation or an incorrect loop bound. Subsequent memory writes then extend beyond the allocated buffer.

Because rlottie processes untrusted JSON-formatted animation input, remote delivery is straightforward. Any application that renders a Lottie file received over the network or loaded from an untrusted source inherits the risk. Confidentiality and integrity remain unaffected, but the availability impact is high — the parser reliably crashes on malformed input.

Root Cause

The root cause is missing validation on numeric fields prior to their use in size arithmetic. When multiplication or addition of attacker-controlled values exceeds the integer type's range, the truncated result silently propagates into allocation and copy routines. This pattern matches CWE-680, where an integer overflow directly enables a downstream buffer overflow. The upstream fix is tracked in GitHub Pull Request #600.

Attack Vector

Exploitation requires a victim to load a crafted Lottie animation using a vulnerable rlottie build. Delivery vectors include websites embedding animations, chat applications, or any client that fetches remote animation assets. No authentication or elevated privileges are required. The vulnerability manifests during parsing, before any application-level trust decisions are made.

No verified public exploit code is available. Refer to the upstream rlottie pull request for technical detail on the corrected size validation.

Detection Methods for CVE-2026-19588

Indicators of Compromise

Repeated crashes in processes that link rlottie, particularly during animation load
Malformed or oversized JSON animation payloads delivered from untrusted origins
Unexpected termination of renderer or preview subprocesses handling .json or .lottie assets

Detection Strategies

Inventory applications and container images that ship rlottie and identify unpatched versions
Inspect crash telemetry for signatures involving rlottie symbols or animation parsing frames
Apply content inspection at ingress to flag Lottie files with anomalous numeric fields or oversized arrays

Monitoring Recommendations

Forward endpoint and application crash logs to a centralized analytics pipeline for correlation
Track process termination events tied to renderers that load third-party animation content
Alert on repeated denial-of-service patterns affecting the same client process across a user population

How to Mitigate CVE-2026-19588

Immediate Actions Required

Identify all software dependent on rlottie and prioritize builds exposed to untrusted input
Upgrade to a rlottie release that incorporates the fix from pull request #600
Restrict acceptance of Lottie animations from untrusted sources until patches are deployed

Patch Information

The upstream fix is available in the Samsung rlottie repository via GitHub Pull Request #600. Downstream maintainers should rebuild artifacts against the patched source and redistribute updated packages. Application vendors embedding rlottie statically must recompile and reship affected products.

Workarounds

Disable rendering of remotely delivered Lottie animations in exposed applications
Enforce strict server-side validation of animation file size and JSON structure before delivery to clients
Sandbox animation parsing in an isolated process to contain crashes and limit availability impact

bash

# Verify installed rlottie version and rebuild against patched source
git clone https://github.com/Samsung/rlottie.git
cd rlottie
git log --oneline | head -n 20
# Confirm the merge commit for PR #600 is present before building
mkdir build && cd build
cmake .. && make -j"$(nproc)"