CVE-2026-47311 Overview
CVE-2026-47311 is a heap-based buffer overflow [CWE-122] in Samsung Open Source Escargot, a lightweight JavaScript engine used in resource-constrained environments such as IoT devices. The flaw affects commit 590345cc6258317c5da850d846ce6baaf2afc2d3 of the Escargot runtime. An attacker who convinces a user to process crafted JavaScript content can corrupt heap memory within the engine. Successful exploitation can lead to arbitrary code execution within the context of the host application embedding Escargot. The vulnerability requires local access and user interaction, but yields high impact across confidentiality, integrity, and availability.
Critical Impact
Heap memory corruption in the Escargot JavaScript engine enables arbitrary code execution within the embedding application when a victim processes malicious script content.
Affected Products
- Samsung Open Source Escargot JavaScript engine
- Escargot commit 590345cc6258317c5da850d846ce6baaf2afc2d3
- Applications and embedded devices embedding the affected Escargot build
Discovery Timeline
- 2026-05-19 - CVE-2026-47311 published to the National Vulnerability Database
- 2026-05-19 - Last updated in NVD database
Technical Details for CVE-2026-47311
Vulnerability Analysis
The vulnerability is a heap-based buffer overflow classified under [CWE-122]. Escargot allocates objects and buffers on the heap during JavaScript execution. The affected code path writes data beyond the bounds of an allocated heap region. This corruption can overwrite adjacent heap metadata, object headers, or function pointers used by the runtime.
Because Escargot embeds directly into host applications, memory corruption inside the engine compromises the entire host process. Attackers can leverage the overflow to influence subsequent allocations, manipulate JavaScript object internals, or hijack control flow. The advisory does not disclose a public proof-of-concept exploit at this time. The fix has been submitted through the upstream GitHub Pull Request by Samsung.
Root Cause
The root cause is missing or incorrect bounds enforcement when writing into a heap-allocated buffer within Escargot. The engine fails to validate that the destination buffer has sufficient capacity for the data being written. Refer to the upstream pull request for the specific code path and corrective changes.
Attack Vector
The attack vector is local with required user interaction. An attacker delivers crafted JavaScript content that the victim processes through an application embedding the vulnerable Escargot build. Triggering the vulnerable code path corrupts the heap and can result in arbitrary code execution in the embedding process. The technical reference for this issue is the GitHub Pull Request by Samsung, which contains the source-level details.
Detection Methods for CVE-2026-47311
Indicators of Compromise
- Unexpected crashes or segmentation faults in processes embedding the Escargot JavaScript engine
- Heap corruption signatures reported by allocator diagnostics such as glibc malloc checks or AddressSanitizer
- Anomalous child process creation originating from applications that execute untrusted JavaScript through Escargot
Detection Strategies
- Inventory binaries and firmware images for the affected Escargot commit 590345cc6258317c5da850d846ce6baaf2afc2d3 and any derivative builds
- Run fuzz testing with sanitizer-enabled Escargot builds against suspect JavaScript inputs to surface heap overflows
- Monitor process telemetry for crash loops, abnormal memory allocation patterns, and exception signatures in Escargot host processes
Monitoring Recommendations
- Forward host crash dumps and application logs from Escargot-embedded systems to a central analytics pipeline
- Alert on unexpected process termination, post-crash restarts, and code execution events spawned by JavaScript runtime hosts
- Correlate execution of untrusted script content with subsequent file system, network, or persistence activity on the same host
How to Mitigate CVE-2026-47311
Immediate Actions Required
- Identify all systems, applications, and embedded devices that ship Escargot at commit 590345cc6258317c5da850d846ce6baaf2afc2d3
- Restrict execution of untrusted JavaScript in any application embedding the affected Escargot build until patched
- Apply the upstream fix from the Samsung Escargot repository as soon as it is merged and released
Patch Information
The vendor has submitted a fix through the upstream GitHub Pull Request by Samsung. Rebuild Escargot from a revision that includes this pull request and redeploy all dependent applications and firmware images. Validate the resulting builds with regression and fuzz testing before production rollout.
Workarounds
- Block or sandbox processing of untrusted JavaScript content within applications that embed the vulnerable Escargot build
- Run Escargot host processes with reduced privileges and operating system level hardening such as ASLR and DEP
- Segment IoT and embedded devices running Escargot from sensitive network zones until updated firmware is deployed
# Configuration example: rebuild Escargot from a fixed revision
git clone https://github.com/Samsung/escargot.git
cd escargot
git fetch origin pull/1565/head:fix-cve-2026-47311
git checkout fix-cve-2026-47311
cmake -H. -Bout -DESCARGOT_MODE=release
make -Cout -j
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
