Slack Morphism verifier errors disclose valid HMACs in the logs

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.0043, the 37th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 31 Oct 2026, 14:24 UTC First seen by agentprime
2. 31 Oct 2026, 14:24 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-26w4-8w32-4x3v
• OSV: GHSA-26w4-8w32-4x3v
• github.com/abdolence/slack-morphism-rust/security/advisories/GHSA-26w4-8w32-4x3v
• github.com/abdolence/slack-morphism-rust/pull/387
• github.com/abdolence/slack-morphism-rust/commit/ac95d0d4539d0eac548a8db99c51c0c1ae832756
• github.com/abdolence/slack-morphism-rust
• github.com/abdolence/slack-morphism-rust/releases/tag/v2.28.0

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.