CVE-2023-32691: gost (GO Simple Tunnel) is a simple tunnel written in golang

Q: How do I fix CVE-2023-32691?

go simple tunnel: upgrade to newer than 2.11.5. Exact commands for each OS are on this page.

Q: Is CVE-2023-32691 being exploited?

CVE-2023-32691 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-2023-32691 affect?

CVE-2023-32691 affects go simple tunnel. Severity is medium (CVSS 5.9). gost (GO Simple Tunnel) is a simple tunnel written in golang. Sensitive secrets such as passwords, token and API keys should be compared only using a constant-time comparison function. Untrusted input, sourced from a HTTP header, is compare

Q: How urgent is CVE-2023-32691?

Priority 37/100. Public exploit reference

Routine

MEDIUM 5.9UPGRADE

CVE-2023-32691 is a medium-severity flaw (CVSS 5.9) affecting go simple tunnel. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

gost (GO Simple Tunnel) is a simple tunnel written in golang. Sensitive secrets such as passwords, token and API keys should be compared only using a constant-time comparison function. Untrusted input, sourced from a HTTP header, is compared directly with a secret. Since this comparison is not secure, an attacker can mount a side-channel timing attack to guess the password. As a workaround, this can be easily fixed using a constant time comparing

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.6% (top 53%)
CISA exploited list	No
Weakness	CWE-203
Published	2023-05-30
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: go simple tunnel project

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

Am I affected?

Timeline

2023-05-30 04:15 UTCPublished CVE record published
2026-06-17 05:59 UTCUpdated Record last modified

go simple tunnel project go simple tunnel UPGRADE

Affected: <= 2.11.5

Fixed in: newer than 2.11.5

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy go-simple-tunnel || rpm -q go-simple-tunnel || go-simple-tunnel --version

2. UPGRADE to newer than 2.11.5 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade go-simple-tunnel

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade go-simple-tunnel

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-2023-32691?

go simple tunnel: upgrade to newer than 2.11.5. Exact commands for each OS are on this page.

Is CVE-2023-32691 being exploited?

CVE-2023-32691 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-2023-32691 affect?

CVE-2023-32691 affects go simple tunnel. Severity is medium (CVSS 5.9). gost (GO Simple Tunnel) is a simple tunnel written in golang. Sensitive secrets such as passwords, token and API keys should be compared only using a constant-time comparison function. Untrusted input, sourced from a HTTP header, is compare

How urgent is CVE-2023-32691?

Priority 37/100. Public exploit reference

Software pages

Go (Golang) vulnerabilities

References

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