Base64 Decoder 1.1.2 Local Buffer Overflow SEH Egghunter
Published Mar 24, 2026
8.6
HIGHCVSS 4.0
EPSS 0.26%
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.
Affected products
-
- Version 1.1.2StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 4Mhz | Base64 Decoder | n/a |
|
- 1.1.2
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
1 other source (NVD) ▾
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
1 other source (CVE.org) ▾
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
PoCAutomatable
NoTechnical Impact
TotalDecision
n/aAssessed Mar 24, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 2, 2026.
Score over time
Mar–Oct 2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 0.26% (0.00262) | 16.35th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.26% (0.00262) | 17.30th | v5 (v2026.06.15) |
| Mar 24, 2026 | 0.01% (0.00013) | 2.25th | v4 (v2025.03.14) |
References (4)
- http://4mhz.de/b64dec.html productRelease Notes
- http://4mhz.de/download.php?file=b64dec-1-1-2.zip product
- https://www.exploit-db.com/exploits/46625 exploit
- https://www.vulncheck.com/advisories/base64-decoder-local-buffer-overflow-seh-egghunter third-party-advisoryThird Party Advisory
| Link | Providers | Tags |
|---|---|---|
| http://4mhz.de/b64dec.html | productRelease Notes | |
| http://4mhz.de/download.php?file=b64dec-1-1-2.zip | product | |
| https://www.exploit-db.com/exploits/46625 | exploit | |
| https://www.vulncheck.com/advisories/base64-decoder-local-buffer-overflow-seh-egghunter | third-party-advisoryThird Party Advisory |
Change history (0)
No recorded changes yet.