# GHSA-c32p-wcqj-j677: CometBFT has inconsistencies between how commit signatures are verified and how block time is derived > Attackers can manipulate block timestamps by exploiting signature verification inconsistencies, affecting blockchain consensus integrity. - **Severity:** Not scored - **Exploited in the wild:** Not known - **Login needed:** An administrator - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 23 Jan 2026 - **Also known as:** GO-2026-4361 ## What is GHSA-c32p-wcqj-j677? GHSA-c32p-wcqj-j677 is a vulnerability in github.com/cometbft/cometbft, published on 23 Jan 2026. An attacker needs administrator access to exploit it, with no action from the victim. ### Official description # CSA-2026-001: Tachyon ## Description **Name:** CSA-2026-001: Tachyon **Criticality:** Critical (Catastrophic Impact; Possible Likelihood per [ACMv1.2](https://github.com/interchainio/security/blob/main/resources/CLASSIFICATION_MATRIX.md)) **Affected versions:** All versions of CometBFT **Affected users:** Validators and protocols relying on block timestamps ## Description A consensus-level vulnerability was discovered in CometBFT's "BFT Time" implementation due to an inconsistency between how commit signatures are verified and how block time is derived. This breaks a core BFT Time guarantee: "A faulty process cannot arbitrarily increase the Time value." ## Impact Downstream impact on chains affects any module, smart contract, or system that relies on the block timestamp. ## Patches The new CometBFT releases [v0.38.21](https://github.com/cometbft/cometbft/releases/tag/v0.38.21) and [v0.37.18](https://github.com/cometbft/cometbft/releases/tag/v0.37.18) fix this issue. The `main` unreleased branch is also patched. ## Workarounds There are no effective workarounds for this vulnerability. Upgrading to patched versions is required. ## Timeline - January 8, 2026, 5:27PM UTC: Issue reported to Cosmos Bug Bounty Program - January 9, 2026, 4:55AM UTC: Issue triaged and validated by core team - January 12, 2026, 10:25PM UTC: Core team completes patch for the issue - January 13, 2026 4:41PM UTC: Pre-notification delivered to ecosystem partners - January 23, 2026, 3:00PM UTC: Patch made available ## Credits This issue was reported to the Cosmos Bug Bounty Program on HackerOne. Credit to SEAL 911 and [QED Audit](https://x.com/QED_Audit) for the discovery and help with the patch. If you believe you have found a bug in the Cosmos Stack or would like to contribute to the program by reporting a bug, please see https://hackerone.com/cosmos. If you have questions about Cosmos security efforts, please reach out to our official communication channel at security@cosmoslabs.io. A Github Security Advisory for this issue is available in the CometBFT repository. For more information about CometBFT, see https://docs.cometbft.com/. ## Which versions are affected by GHSA-c32p-wcqj-j677? 5 open source packages ship an affected version, including github.com/cometbft/cometbft. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `github.com/cometbft/cometbft` | Go | All versions | 0.37.18, 0.38.21 | | `github.com/cometbft/cometbft` | Go | All versions | 0.37.18 | | `github.com/cometbft/cometbft` | Go | All versions | 0.37.18 | | `github.com/cometbft/cometbft` | Go | From 0.38.0-alpha.1 | 0.38.21 | | `github.com/cometbft/cometbft` | Go | From 0.38.0-alpha.1 | 0.38.21 | ## How do I fix GHSA-c32p-wcqj-j677? Upgrade github.com/cometbft/cometbft to a fixed version for your release line: 0.37.18 or 0.38.21. ## Is GHSA-c32p-wcqj-j677 being exploited? There is no known exploitation of GHSA-c32p-wcqj-j677 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for GHSA-c32p-wcqj-j677 and fix it if it is affected. What it is: GHSA-c32p-wcqj-j677 is a vulnerability in github.com/cometbft/cometbft, published on 23 Jan 2026. An attacker needs administrator access to exploit it, with no action from the victim. Exploitation: There is no known exploitation of GHSA-c32p-wcqj-j677 in the wild and no public exploit code. Affected packages and fixed versions: - github.com/cometbft/cometbft (Go): affected all versions; fixed in 0.37.18, 0.38.21 - github.com/cometbft/cometbft (Go): affected all versions; fixed in 0.37.18 - github.com/cometbft/cometbft (Go): affected all versions; fixed in 0.37.18 - github.com/cometbft/cometbft (Go): affected from 0.38.0-alpha.1; fixed in 0.38.21 - github.com/cometbft/cometbft (Go): affected from 0.38.0-alpha.1; fixed in 0.38.21 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/GHSA-c32p-wcqj-j677/ (Markdown: https://insights.sbomify.com/GHSA-c32p-wcqj-j677/index.md) ``` ## Sources - OSV: https://osv.dev/vulnerability/GHSA-c32p-wcqj-j677 --- From sbomify Insights: https://insights.sbomify.com/GHSA-c32p-wcqj-j677/ Summaries are generated and may contain mistakes; the official description above is the record.