CVE•Published 2026-03-24•Modified 2026-06-03•1 article on news•7 live references•NVD data
CVE-2019-256344mhz · Base64_decoder
Vulnerability data via NVD (ingested)
CVSS v3.1
8.4
HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS percentile
5
Exploit Prediction Scoring System · top 95% of all CVEs
Weaknesses (CWE)
Description
Base64 Decoder 1.1.2 contains a stack-based buffer overflow vulnerability that allows local attackers to execute arbitrary code by triggering a structured exception handler (SEH) overwrite. Attackers can craft a malicious input file that overflows a buffer, overwrites the SEH chain with a POP-POP-RET gadget address, and uses an egghunter payload to locate and execute shellcode for code execution.
Timeline
Published 2026-03-24
Modified 2026-06-03
External references
Search for exposed instances
Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).
Shodan · vuln tag0 hosts
vuln:CVE-2019-25634Hosts Shodan has explicitly fingerprinted as vulnerable.
Shodan · product + version
product:"4mhz Base64 Decoder" version:"1.1.2"Version-pinned fingerprint from NVD's first vulnerable CPE.
Shodan · banner/body mention
http.html:"Base64 Decoder"HTTP body or banner mentions "Base64 Decoder" — catches deploys Shodan didn't identify as a product.
More intel sources (5)
Shodan report
vuln:CVE-2019-25634Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2019-25634Censys host search filtered to this CVE id.
grep.app
CVE-2019-25634Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2019-25634GitHub code search for direct mentions.
Google dork
"CVE-2019-25634" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.
Known PoCs on GitHub
No public proof-of-concept repositories found for CVE-2019-25634 on GitHub.