Jujutsu does not have SHA-1 collision detection

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.8 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary Jujutsu 0.28.0 and earlier rely on versions of gitoxide that use SHA-1 hash implementations without any collision detection, leaving them vulnerable to hash collision attacks. Details This is a result of the underlying CVE-2025-31130 / GHSA-2frx-2596-x5r6 vulnerability in the gitoxide library Jujutsu uses to interact with Git repositories; see that advisory for technical details. This separate advisory is being issued due to the downstream impact on users of Jujutsu. Impact An attacker with the ability to mount a collision attack on SHA-1 like the SHAttered or SHA-1 is a Shambles attacks could create two distinct Git objects with the same hash. This is becoming increasingly affordable for well‐resourced attackers, with the Shambles researchers in 2020 estimating $45k for a chosen‐prefix collision or $11k for a classical collision, and projecting less than $10k for a chosen‐prefix collision by 2025. The result could be used to disguise malicious repository contents, or…

Published by the source

7 Apr 2025, 16:40 UTC

Last modified by the source

7 Apr 2025, 16:40 UTC

Source last checked

26 Oct 2026, 15:38 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-794x-2rpg-rfgr

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# Patch Next advisory brief: GHSA-794x-2rpg-rfgr

Advisory: Jujutsu does not have SHA-1 collision detection
IDs: GHSA-794x-2rpg-rfgr
Record: https://patchnext.com/advisories/ghsa-794x-2rpg-rfgr (revision 1, source checked 26 Oct 2026, 15:38 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: jj-lib 0.28.1; jj-cli 0.28.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io jj-lib: affected < 0.28.1; fixed in 0.28.1
- crates.io jj-cli: affected < 0.28.1; fixed in 0.28.1

## Suggested inspection (read-only)
- crates.io jj-lib: check the installed version with your package manager.
- crates.io jj-cli: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on jj-lib, jj-cli.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-794x-2rpg-rfgr (GitHub-reviewed advisory GHSA-794x-2rpg-rfgr lists affected ranges: crates.io jj-lib >=0 =0 <0.28.1)

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