CVE-2026-2259 – This CVE describes a memory corruption vulnerab... (How to Fix)

📋 TL;DR

This CVE describes a memory corruption vulnerability in the lobster::Parser::ParseStatements function of the aardappel lobster library. Attackers with local access can exploit this to potentially execute arbitrary code or cause denial of service. Only systems running lobster up to version 2025.4 are affected.

💻 Affected Systems

Products:

aardappel lobster

Versions: Up to and including 2025.4

Operating Systems: All platforms running lobster

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems where lobster library is used for parsing. The vulnerability is in the parser component and requires local access to exploit.

📦 What is this software?

Lobster by Strlen

View all CVEs affecting Lobster →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Local privilege escalation leading to full system compromise, arbitrary code execution, or complete system crash.

🟠

Likely Case

Application crash or denial of service affecting the lobster parser functionality.

🟢

If Mitigated

Limited impact due to local-only attack vector and proper access controls restricting local user privileges.

🌐 Internet-Facing: LOW - The vulnerability requires local access and cannot be exploited remotely.

🏢 Internal Only: MEDIUM - Local users could exploit this, but impact depends on user privileges and system configuration.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploit code has been publicly disclosed in GitHub repositories. Attack requires local access to the system.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Versions after commit 2f45fe860d00990e79e13250251c1dde633f1f89

Vendor Advisory: https://github.com/aardappel/lobster/issues/396

Restart Required: Yes

Instructions:

1. Update lobster to a version containing commit 2f45fe860d00990e79e13250251c1dde633f1f89
2. Rebuild any applications using the lobster library
3. Restart affected services

🔧 Temporary Workarounds

Restrict local user access

all

Limit local user privileges to reduce attack surface

Disable vulnerable functionality

all

If possible, disable or restrict use of the lobster parser component

🧯 If You Can't Patch

Implement strict access controls to limit local user privileges
Monitor systems for unusual process behavior or crashes related to lobster parser

🔍 How to Verify

Check if Vulnerable:

Check lobster version: if version is 2025.4 or earlier, system is vulnerable

Check Version:

Check lobster documentation or build information for version details

Verify Fix Applied:

Verify commit 2f45fe860d00990e79e13250251c1dde633f1f89 is present in the lobster source code

📡 Detection & Monitoring

Log Indicators:

Unexpected application crashes
Memory access violation errors in logs
Abnormal process termination

Network Indicators:

None - local-only vulnerability

SIEM Query:

Search for: 'lobster parser crash' OR 'memory corruption' AND process_name contains 'lobster'

📊 Metadata

CVE ID: CVE-2026-2259

CVSS v3 Score: 3.3 (LOW)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

CWE: CWE-119

EPSS Score: 0.02% exploit probability (2.7th percentile)

Published: February 10, 2026

Last Updated: February 17, 2026

🔗 References

https://github.com/aardappel/lobster/ Product
https://github.com/aardappel/lobster/commit/2f45fe860d00990e79e13250251c1dde633f1f89 Patch
https://github.com/aardappel/lobster/issues/396 Patch,Vendor Advisory,Issue Tracking
https://github.com/aardappel/lobster/issues/396#issuecomment-3849019040 Patch,Vendor Advisory,Issue Tracking
https://github.com/oneafter/0204/blob/main/lob2/repro.lobster Exploit
https://vuldb.com/?ctiid.345006 Permissions Required,VDB Entry
https://vuldb.com/?id.345006 Third Party Advisory,VDB Entry
https://vuldb.com/?submit.753168 Exploit,Third Party Advisory,VDB Entry

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