CVE-2026-108978: Samsung rlottie Buffer Overflow Vulnerability

CVE-2026-108978 Overview

CVE-2026-108978 is a heap-based buffer overflow vulnerability in Samsung's open source rlottie library, a C++ renderer for Lottie animation files. The flaw is triggered through environment variables and affects commit e57b094f03c39a751a1fded6f7d6c13f1ed95ec9. Exploitation requires local access and user interaction, and results in an availability impact without affecting confidentiality or integrity. The weakness is classified under CWE-122: Heap-based Buffer Overflow.

Critical Impact
A local attacker can craft malicious environment variable input to overflow a heap buffer in rlottie, causing process crash and denial of service in applications that embed the library.

Affected Products

Samsung rlottie at commit e57b094f03c39a751a1fded6f7d6c13f1ed95ec9
Applications and services that statically or dynamically link the affected rlottie revision
Downstream distributions packaging the vulnerable commit

Discovery Timeline

2026-10-11 - CVE-2026-108978 published to NVD
2026-10-16 - Last updated in NVD database

Technical Details for CVE-2026-108978

Vulnerability Analysis

The vulnerability resides in rlottie, Samsung's open source library for parsing and rendering Lottie JSON animations. The affected code path reads data from environment variables and writes into a fixed-size heap-allocated buffer without validating that the input length fits the destination. When the input exceeds the allocated capacity, adjacent heap memory is corrupted.

The outcome is process termination or undefined behavior inside any host application that initializes rlottie while attacker-controlled environment variables are set. Because the attack vector is local and requires user interaction, exploitation typically depends on tricking a privileged user into launching a process with poisoned environment state.

See the upstream GitHub Pull Request Discussion for the specific code path and remediation discussion.

Root Cause

The root cause is missing bounds checking on environment variable data copied into a heap buffer, consistent with [CWE-122]. The library trusts the length of the configuration value supplied via the process environment and performs an unchecked copy into a smaller destination allocation.

Attack Vector

An attacker with local access to a system running software that embeds rlottie sets a crafted environment variable before the target process starts. When the victim user launches the application, rlottie reads the value, overflows the heap buffer, and crashes the process. Successful corruption of allocator metadata could, in constrained scenarios, extend beyond availability impact, though the published scoring reflects crash impact only.

No verified public exploit code is available. The vulnerability mechanism is described in the upstream pull request linked above.

Detection Methods for CVE-2026-108978

Indicators of Compromise

Repeated crash signatures or SIGABRT/SIGSEGV events in processes linking rlottie, especially during startup or animation load.
Core dumps showing heap corruption diagnostics such as glibc malloc(): corrupted or AddressSanitizer heap-buffer-overflow reports referencing rlottie symbols.
Unexpected environment variables set in user sessions or service unit files that reference rlottie configuration keys with abnormally long values.

Detection Strategies

Inventory applications and container images for the rlottie commit e57b094f03c39a751a1fded6f7d6c13f1ed95ec9 using SBOM tooling.
Build the library with AddressSanitizer in test environments to surface the overflow deterministically under fuzzed environment input.
Hunt for process launches where parent processes modify child environment blocks with oversized values before invoking binaries that depend on rlottie.

Monitoring Recommendations

Collect endpoint process telemetry including environment variable content where supported, and alert on anomalies in length or character distribution.
Forward application crash logs to a central analytics pipeline and correlate repeated crashes to common users, hosts, or binaries.
Monitor file integrity on service unit files, shell profiles, and container entrypoints that define environment variables for affected applications.

How to Mitigate CVE-2026-108978

Immediate Actions Required

Identify all internal and third-party software that bundles rlottie and determine whether they ship the affected commit.
Restrict local access to systems running vulnerable applications, and audit user accounts able to modify environment variables for shared services.
Rebuild affected binaries against a patched upstream revision once available, and redeploy container images that pin the vulnerable commit.

Patch Information

Remediation is tracked upstream in the Samsung rlottie pull request #609. Apply the merged fix or update to a release that includes the bounds-checked environment variable handling. Downstream package maintainers should rebuild and republish affected artifacts.

Workarounds

Unset or sanitize the rlottie-specific environment variables referenced in the pull request before launching affected applications.
Enforce least-privilege execution so that unprivileged users cannot inject environment variables into higher-privilege processes.
Enable allocator hardening such as glibc MALLOC_CHECK_ or compile with stack and heap protections to reduce exploitability pending patch deployment.

bash

# Configuration example: strip rlottie-related env vars for a systemd service
# /etc/systemd/system/myapp.service.d/override.conf
[Service]
UnsetEnvironment=LOTTIE_DEBUG LOTTIE_CACHE_PATH