CVE-2026-2940
📋 TL;DR
This CVE describes a remote out-of-bounds write vulnerability in Zaher1307's tiny_web_server that could allow attackers to execute arbitrary code or crash the server. Anyone using this web server software up to commit 8d77b1044a0ca3a5297d8726ac8aa2cf944d481b is affected. The vulnerability exists in the URL handler component and can be exploited without authentication.
💻 Affected Systems
- Zaher1307 tiny_web_server
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or installation of persistent malware.
Likely Case
Server crash (denial of service) or limited memory corruption allowing information disclosure.
If Mitigated
Minimal impact if proper network segmentation and least privilege principles are implemented.
🎯 Exploit Status
Exploit has been publicly disclosed and the vulnerability is in a core URL handling function, making exploitation straightforward.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown - project maintainer has not responded to issue report
Vendor Advisory: None available
Restart Required: Yes
Instructions:
1. Monitor the GitHub repository for patches. 2. Consider switching to alternative web server software. 3. If a patch becomes available, rebuild from source with the fix.
🔧 Temporary Workarounds
Network Access Control
linuxRestrict network access to the web server using firewall rules
iptables -A INPUT -p tcp --dport [PORT] -s [TRUSTED_NETWORK] -j ACCEPT
iptables -A INPUT -p tcp --dport [PORT] -j DROP
Process Isolation
linuxRun the web server in a container or with minimal privileges
docker run --read-only --cap-drop=ALL -p 80:80 [IMAGE]
setcap -r /path/to/tiny_web_server
🧯 If You Can't Patch
- Replace tiny_web_server with alternative web server software (nginx, Apache, lighttpd)
- Implement web application firewall (WAF) rules to block malicious URL patterns
🔍 How to Verify
Check if Vulnerable:
Check if your tiny_web_server binary was built from a commit before or including 8d77b1044a0ca3a5297d8726ac8aa2cf944d481bCheck Version:
git log --oneline -1 (if built from source) or check build metadataVerify Fix Applied:
Verify the source code no longer contains the vulnerable URL handler logic from tiny.c📡 Detection & Monitoring
Log Indicators:
- Unusual long URLs or malformed HTTP requests
- Server crash/restart logs
- Memory access violation errors
Network Indicators:
- HTTP requests with unusually long or malformed URLs
- Traffic patterns suggesting exploitation attempts
SIEM Query:
source="web_server.log" AND (url_length>1024 OR status=500) | stats count by src_ip