CVE-2026-91826: Samsung rlottie Stack Buffer Overflow — Detection and Remediation Guide

Zero Day Initiative published ZDI-26-714 for a stack-based buffer overflow in Samsung rlottie, tracked as CVE-2026-91826 and rated CVSS 7.8. The advisory language is important: remote attackers can execute arbitrary code, but interaction with the rlottie library is required and the exact pathway depends on how the embedding application renders or previews attacker-controlled Lottie/JSON animation data.

For defenders, this is not a drop-everything critical CVSS 10 event, but it is a serious parser-memory-corruption bug in a component that often sits inside high-volume user workflows: messaging previews, mobile/Tizen surfaces, media thumbnails, design tools, web views, and embedded apps that auto-render animation. A CVSS 7.8 unauthenticated code-execution issue in a parser should be treated as patch-now where vendor updates exist, and isolate-and-monitor where they do not.

As of the source item, the public summary does not confirm in-the-wild exploitation, public PoC weaponization, or CISA KEV inclusion. That means the correct posture is proactive: identify every place rlottie parses untrusted animation files, reduce exposure to auto-rendering, instrument crash and child-process telemetry around those paths, and verify remediation after Samsung or downstream application vendors ship fixes.

Technical Analysis

Affected component: Samsung rlottie, a C++ library used to render Lottie-style vector animations exported as JSON. The ZDI summary does not enumerate affected versions or platforms in the text provided, so do not assume only Samsung handset firmware is exposed. Any product that bundles rlottie or a forked copy may inherit risk until the embedded library is updated.

Vulnerability class: stack-based buffer overflow leading to arbitrary code execution. Stack overflows in parser libraries are especially operationally relevant because the vulnerable code runs in the context of the host process. If rlottie is linked into a privileged renderer, broker, thumbnail service, or mobile app component, the blast radius is whatever that process can access.

Attack chain, defensive view:

1. Attacker delivers a crafted Lottie/JSON animation through a channel that reaches an rlottie-backed parser: message attachment, web preview, MDM-enrolled app content, synced design asset, sideloaded media, or app-specific import workflow.
2. The host application parses or renders the object. The trigger may require explicit user open in one implementation, or automatic thumbnail/preview generation in another. ZDI explicitly warns that the interaction pathway may vary by implementation.
3. Malformed animation input overflows a stack buffer in rlottie parsing code, corrupting adjacent stack memory.
4. If exploitation succeeds, execution occurs inside the host process. From there, expect post-exploitation behaviors consistent with that host: spawning a shell or interpreter, writing payloads to temp/cache directories, establishing outbound connections, or attempting persistence through the parent application rather than as a standalone new service.

Defender assumptions to avoid: Do not assume exploitation requires a Samsung-branded executable. Many vulnerabilities like this surface in third-party apps that statically link or vendor older copies. Also do not assume a low CVSS means low urgency: parser bugs become dangerous when combined with auto-preview, sandbox escape, chained mobile exploitation, or high-value user targeting.

Exploitation status: Based only on the provided ZDI summary, treat active exploitation as unconfirmed. Continue to monitor the ZDI advisory and your vendor channels for updates, but do not wait for proof of exploitation to inventory and reduce exposure.

Detection & Response

The highest-value telemetry is not a magic IOC; it is correlation between untrusted animation handling, parser instability, and post-parse execution. Baseline which processes legitimately render Lottie assets, then alert when those processes crash, spawn shells/interpreters, or make unusual outbound connections shortly after new media arrives.

---
title: Suspicious Shell or Interpreter Spawned By Lottie/rlottie Renderer
description: Detects processes whose image or command line references rlottie/Lottie rendering spawning shells, script interpreters, or common post-exploitation binaries after parsing animation content. Deploy only after baselining legitimate renderer hosts.
references:
  - http://www.zerodayinitiative.com/advisories/ZDI-26-714/
  - https://attack.mitre.org/techniques/T1059/
author: Security Arsenal
id: 8f5a4b2c-9d3e-4a1b-b7c6-2d4e6f8a0b12
status: experimental
date: 2026/04/06
tags:
  - attack.execution
  - attack.t1059
logsource:
  category: process_creation
  product: linux
detection:
  selection_parent:
    ParentImage|contains:
      - 'rlottie'
      - 'lottie'
    ParentCommandLine|contains:
      - 'rlottie'
      - 'lottie'
      - '.json'
  selection_child:
    Image|endswith:
      - '/sh'
      - '/bash'
      - '/dash'
      - '/zsh'
      - '/python'
      - '/python3'
      - '/perl'
      - '/ruby'
      - '/node'
      - '/curl'
      - '/wget'
  condition: selection_parent and selection_child
falsepositives:
  - Legitimate animation build pipelines
  - Developer workstations testing Lottie assets
  - CI render farms
level: high
---
title: Lottie Renderer Process Making Uncommon Outbound Connection
description: Detects network connections from processes associated with rlottie/Lottie rendering. Use as a low-noise hunt when paired with asset inventory and recent media ingestion context.
references:
  - http://www.zerodayinitiative.com/advisories/ZDI-26-714/
  - https://attack.mitre.org/techniques/T1071/
author: Security Arsenal
id: 3b1c7d94-5e2f-4a68-9c01-7e8d9f0a2345
status: experimental
date: 2026/04/06
tags:
  - attack.command_and_control
  - attack.t1071
logsource:
  category: network_connection
  product: linux
detection:
  selection:
    Image|contains:
      - 'rlottie'
      - 'lottie'
  filter_expected_ports:
    DestinationPort:
      - 80
      - 443
  condition: selection and not filter_expected_ports
falsepositives:
  - Renderers fetching remote assets
  - Telemetry from embedded mobile frameworks
level: medium

// Hunt: rlottie/Lottie parser instability followed by suspicious execution
let lookback = 14d;
let renderer_terms = dynamic(['rlottie','lottie']);
let shells = dynamic(['sh','bash','dash','zsh','python','python3','perl','ruby','node','curl','wget']);
union isfuzzy=true
(
  Syslog
  | where TimeGenerated >= ago(lookback)
  | where SyslogMessage has_any ('rlottie','lottie') and SyslogMessage has_any ('segfault','stack','overflow','crash','core dumped')
  | project TimeGenerated, Computer, ProcessName, SyslogMessage, SourceIP
),
(
  CommonSecurityLog
  | where TimeGenerated >= ago(lookback)
  | where Message has_any ('rlottie','lottie') and Message has_any ('segfault','crash','core')
  | project TimeGenerated, DeviceName, SourceProcessName, Message, SourceIP
),
(
  DeviceProcessEvents
  | where TimeGenerated >= ago(lookback)
  | where InitiatingProcessFileName has_any (renderer_terms) or InitiatingProcessCommandLine has_any (renderer_terms)
  | where FileName in~ (shells) or ProcessCommandLine has_any ('curl ','wget ','base64','/tmp/','chmod +x')
  | project TimeGenerated, DeviceName, InitiatingProcessFileName, InitiatingProcessCommandLine, FileName, ProcessCommandLine, AccountName, RemoteIP
)
| order by TimeGenerated desc

-- Inventory likely rlottie consumers and recent crash artifacts on Linux endpoints
LET procs = SELECT Pid, Name, Exe, CommandLine, Username, CreateTime
FROM pslist()
WHERE Exe =~ 'rlottie|lottie'
   OR CommandLine =~ 'rlottie|lottie|\.json'

LET cores = SELECT FullPath, Size, ModTime
FROM glob(globs=['/var/lib/systemd/coredump/*','/var/lib/apport/coredump/*','/tmp/core*','/data/tombstones/*'])
WHERE FullPath =~ 'core|tombstone'

SELECT 'process' AS ArtifactType, Pid, Name, Exe, CommandLine, Username, CreateTime, '' AS FullPath, 0 AS Size, '' AS ModTime FROM procs
UNION ALL
SELECT 'core_artifact' AS ArtifactType, 0 AS Pid, '' AS Name, '' AS Exe, '' AS CommandLine, '' AS Username, '' AS CreateTime, FullPath, Size, ModTime FROM cores

#!/usr/bin/env bash
# CVE-2026-91826 rlottie exposure inventory and containment aid - run as root on Linux/Android-like hosts where permitted.
set -euo pipefail

printf '%s
' '== Linked library visibility =='
(ldconfig -p 2>/dev/null | grep -Ei 'rlottie|lottie' || true)

printf '%s
' '== Files that look like rlottie copies =='
find / -xdev \( -iname '*rlottie*' -o -iname '*lottie*' \) -type f 2>/dev/null | head -500

printf '%s
' '== Running processes with rlottie/lottie mappings or command lines =='
for p in /proc/[0-9]*; do
  pid=${p#/proc/}
  if grep -Eiq 'rlottie|lottie' "$p/maps" 2>/dev/null || tr '\0' ' ' < "$p/cmdline" 2>/dev/null | grep -Eiq 'rlottie|lottie'; then
    printf 'PID=%s CMD=' "$pid"
    tr '\0' ' ' < "$p/cmdline" 2>/dev/null || true
    printf '\n'
  fi
done

printf '%s
' '== Package manager candidates =='
(command -v dpkg >/dev/null && dpkg -l | grep -Ei 'rlottie|lottie|samsung') || true
(command -v rpm >/dev/null && rpm -qa | grep -Ei 'rlottie|lottie|samsung') || true
(command -v apk >/dev/null && apk info | grep -Ei 'rlottie|lottie|samsung') || true
(command -v pm >/dev/null && pm list packages | grep -Ei 'lottie|samsung|animation') || true

printf '%s
' '== Crash capture and parser containment recommendations =='
printf '%s
' 'Disable auto-preview/thumbnailing for inbound animation where product policy allows.'
printf '%s
' 'Run renderer in least-privileged sandbox with seccomp, no shell, no outbound network unless required.'
printf '%s
' 'Enable core dump capture centrally and alert on rlottie-linked process crashes.'

Remediation

1. Build a real inventory. Search package databases, mobile/app bundles, container images, Vendored source trees, and static binaries for rlottie or Lottie render forks. Static linkage means normal OS patching will not remediate embedded copies.
2. Patch through the correct owner. Track ZDI-26-714 and Samsung security advisories, then apply updates from the actual consuming product vendor. If an application vendors rlottie internally, require the application vendor to ship an updated build; patching only the OS package can leave the vulnerable copy intact.
3. Do not invent a fixed version. The source summary does not state affected or fixed versions. Change records should reference ZDI-26-714 and CVE-2026-91826, then record the vendor build/commit hash that confirms the rlottie copy was rebuilt after the fix.
4. Reduce untrusted auto-rendering. Until patched, disable automatic preview, thumbnail generation, or inline playback of inbound Lottie/JSON animation in high-risk workflows such as messaging, email, MDM content, and shared design libraries.
5. Sandbox parser execution. Move rendering to a low-privilege process with seccomp/AppArmor/SELinux where available, no shell binaries, no writable executable temp paths, restricted outbound network, and strict file type validation before parse.
6. Harden delivery controls. Block or detonate suspicious .json animation attachments at email/web gateways when business need does not require them. Use content disarm and reconstruction or isolated preview for design-heavy organizations.
7. Validate after remediation. Re-run the inventory script, confirm no vulnerable copies remain in running process maps, crash-test only in a lab with vendor-approved samples, and keep enhanced detection for 30 days after deployment.
8. Escalation threshold. Escalate to incident response if you observe an rlottie-linked crash followed by shell/interpreter execution, payload download, outbound beaconing, or crashes concentrated after inbound media from a single sender/domain.

Related Resources

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