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VulnerabilityPublished Updated

github.com/slack-go/slack · slack-go `SecretsVerifier` accepts empty signing secret without precondition

Affects github.com/slack-go/slackSource GCVE Database

0

CVSS 8.3 High : upgrade to 0.23.1 soon.

Data as of 29 Jun 2026, 22:28 UTC

CVSS 4.0 base score
8.3High
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 0.23.1
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:U

What to do

Upgrade github.com/slack-go/slack to 0.23.1.

Affected software

ProductAffectedFixed in
Gogithub.com/slack-go/slackAffected
  • <0.23.1
Fixed in
  • 0.23.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade to slack-go version 0.23.1 or later, where the vulnerability is fixed by rejecting empty signing secrets. Ensure that the SLACK_SIGNING_SECRET environment variable or configuration is properly set and not empty to prevent this issue.

Description

The slack-go library before version 0.23.1 contains a vulnerability in the SecretsVerifier component where it accepts an empty signing secret without error. This allows an attacker to forge a valid X-Slack-Signature header and bypass Slack request authentication if the application is misconfigured with an empty or unset SLACK_SIGNING_SECRET. The issue is fixed in version 0.23.1, which rejects empty secrets with an explicit error.

References

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