CVE-2023-27830: TightVNC before v2.8.75 allows attackers to escalate privileges on the host operating system via replacing leg

Q: How do I fix CVE-2023-27830?

tightvnc: upgrade to 2.8.75. Exact commands for each OS are on this page.

Q: Is CVE-2023-27830 being exploited?

CVE-2023-27830 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2023-27830 affect?

CVE-2023-27830 affects tightvnc. Severity is critical (CVSS 9.0). TightVNC before v2.8.75 allows attackers to escalate privileges on the host operating system via replacing legitimate files with crafted files when executing a file transfer. This is due to the fact that TightVNC runs in the backend as a hi

Q: How urgent is CVE-2023-27830?

Priority 53/100. Critical severity; Public exploit reference

This month

CRITICAL 9.0UPGRADE

CVE-2023-27830 is a critical-severity flaw (CVSS 9.0) affecting tightvnc. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

TightVNC before v2.8.75 allows attackers to escalate privileges on the host operating system via replacing legitimate files with crafted files when executing a file transfer. This is due to the fact that TightVNC runs in the backend as a high-privileges account.

Why this priority

Critical severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	9.0 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	1.1% (top 35%)
CISA exploited list	No
Weakness	CWE-269
Published	2023-04-12
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: tightvnc

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

Am I affected?

Timeline

2023-04-12 15:15 UTCPublished CVE record published
2026-06-17 05:45 UTCUpdated Record last modified

tightvnc tightvnc UPGRADE

Affected: < 2.8.75

Fixed in: 2.8.75

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 2.8.75 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade tightvnc

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade tightvnc

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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-2023-27830?

tightvnc: upgrade to 2.8.75. Exact commands for each OS are on this page.

Is CVE-2023-27830 being exploited?

CVE-2023-27830 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-2023-27830 affect?

CVE-2023-27830 affects tightvnc. Severity is critical (CVSS 9.0). TightVNC before v2.8.75 allows attackers to escalate privileges on the host operating system via replacing legitimate files with crafted files when executing a file transfer. This is due to the fact that TightVNC runs in the backend as a hi

How urgent is CVE-2023-27830?

Priority 53/100. Critical severity; Public exploit reference

References

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