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Fencer Vulns
medium 5.5

CVE-2020-37121 json

CODE::BLOCKS 16.01 - Buffer Overflow (SEH) UNICODE

published 2026-02-05 9 mo ago modified 2026-08-06 3 mo ago also EUVD-2020-31020

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

CODE::BLOCKS 16.01 contains a buffer overflow vulnerability that allows attackers to execute arbitrary code by overwriting Structured Exception Handler with crafted Unicode characters. Attackers can create a malicious text file with 1982 bytes of buffer and shellcode to trigger remote code execution.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-37121 updated cvss 5.5

code::blocks: CODE::BLOCKS - Buffer Overflow (SEH) UNICODE

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
9 mo ago

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • nutcrackerssecurity.github.io https://nutcrackerssecurity.github.io/posts/windows-exploit-dev-part-7/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 6.7 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CNA 4.0 6.7 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/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

Affected products

  • Code::Blocks Code::Blocks

Classification

Weakness
  • CWE-121 Stack-based Buffer Overflow

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.