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GHSA-gxhx-2686-5h9g

Fix: slack-go/slack@34ad5c0

GHSA-gxhx-2686-5h9g is a security vulnerability in github.com/slack-go/slack. O3 Security confirms whether GHSA-gxhx-2686-5h9g is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

slack-go `SecretsVerifier` accepts empty signing secret without precondition

Also known asGO-2026-5410
Published
May 14, 2026
Updated
Jul 13, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Jul 13, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected
🐹github.com/slack-go/slack

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

SecretsVerifier in slack-go/slack before v0.23.1 accepts an empty signing secret without error. If an application is misconfigured (e.g., an unset or empty SLACK_SIGNING_SECRET), NewSecretsVerifier builds an HMAC-SHA256 keyed with an empty string, allowing an unauthenticated attacker to forge a valid X-Slack-Signature and bypass Slack request authentication. Fixed in v0.23.1, which rejects empty secrets with ErrInvalidConfiguration. This is patched in version 0.23.1.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/slack-go/slackall versions0.23.1

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/slack-go/slack. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update github.com/slack-go/slack to 0.23.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-gxhx-2686-5h9g is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-gxhx-2686-5h9g is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-gxhx-2686-5h9g. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

`SecretsVerifier` in slack-go/slack before v0.23.1 accepts an empty signing secret without error. If an application is misconfigured (e.g., an unset or empty `SLACK_SIGNING_SECRET`), `NewSecretsVerifier` builds an HMAC-SHA256 keyed with an empty string, allowing an unauthenticated attacker to forge a valid `X-Slack-Signature` and bypass Slack request authentication. Fixed in v0.23.1, which rejects empty secrets with `ErrInvalidConfiguration`. This is patched in version 0.23.1.
O3 Security · Impact-Aware SCA

Is GHSA-gxhx-2686-5h9g in your dependencies?

O3 detects GHSA-gxhx-2686-5h9g across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

GHSA-gxhx-2686-5h9g: slack | O3 Security