CVE-2023-40250: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in Hancom HCell on Window

This month

HIGH 8.8DOWNGRADE

CVE-2023-40250 is a high-severity flaw (CVSS 8.8) affecting hcell. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in Hancom HCell on Windows allows Overflow Buffers.This issue affects HCell: 12.0.0.893.

Why this priority

High severity

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.6% (top 53%)
CISA exploited list	No
Weakness	CWE-120
Published	2024-01-12
Last modified	2026-06-17

Publisher (CNA): KrCERT/CC · Vendor: hancom

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2024-01-12 02:15 UTCPublished CVE record published
2026-06-17 06:16 UTCUpdated Record last modified

hancom hcell DOWNGRADE

Affected: 12.0.0.893

Fixed in: no fixed release known

Safe to downgrade to: a release before 12.0.0.893

1. Check installed version

apt-cache policy hcell || rpm -q hcell || hcell --version

2. No fixed release: DOWNGRADE to a release before 12.0.0.893 (Debian / Ubuntu)

apt-cache madison hcell sudo apt install hcell=<VERSION_BEFORE_12.0.0.893> sudo apt-mark hold hcell

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list hcell sudo dnf downgrade hcell-<VERSION_BEFORE_12.0.0.893> sudo dnf versionlock add hcell

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2023-40250?

hcell: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-40250 being exploited?

CVE-2023-40250 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2023-40250 affect?

CVE-2023-40250 affects hcell. Severity is high (CVSS 8.8). Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in Hancom HCell on Windows allows Overflow Buffers.This issue affects HCell: 12.0.0.893.

How urgent is CVE-2023-40250?

Priority 42/100. High severity

Software pages

Windows vulnerabilities

References

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