jj vulnerable to path traversal via crafted Git repositories

Exploitation

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

CVSS 4.0

9.2 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:H/SA:N · score source

EPSS

• CVE-2024-51990: 0.61% estimated exploitation activity in the next 30 days; percentile 49.52 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact Specially crafted Git repositories can cause jj to write files outside the clone. Patches Fixed in 0.23.0. Workarounds Not much other than to not clone repositories from untrusted sources. References Here's the original report from @joernchen: When cloning a crafted Git repository it is possible to let jj write into arbitrary directories. This can be achieved by having file objects which contain path traversals. Reproduction steps: Apply the following patch to Git version v.2.47.0: With this patched git binary we can now apply a crafted patch containing a path traversal to a repository. The patch would look like: Note the traversal ../joernchenwashere in the patch. This now can be committed to a repository using the modified git binary: Now, when cloning that repository with jj git clone the path traversal will write above the worktree directory, allowing arbitrary file writes. I've attached a tar.gz with the demo repo so you don't have to mess with the patched Git at all. For…

Published by the source

7 Nov 2024, 16:18 UTC

Last modified by the source

7 Nov 2024, 16:18 UTC

Source last checked

26 Oct 2026, 15:38 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-88h5-6w7m-5w56

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# Patch Next advisory brief: CVE-2024-51990

Advisory: jj vulnerable to path traversal via crafted Git repositories
IDs: CVE-2024-51990, GHSA-88h5-6w7m-5w56
Record: https://patchnext.com/advisories/cve-2024-51990 (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: Critical (CVSS 9.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: jj-lib 0.23.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io jj-lib: affected < 0.23.0; fixed in 0.23.0

## Suggested inspection (read-only)
- crates.io jj-lib: 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.
- 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-88h5-6w7m-5w56 (GitHub-reviewed advisory GHSA-88h5-6w7m-5w56 lists affected ranges: crates.io jj-lib >=0 <0.23.0)

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