simple-git: unsafe-operations plugin bypass via git long-option abbreviation (--receive-p/--exe) -> command execution (residual of CVE-2026-28291)

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

simple-git, an interface for running git commands in any node.js application, enables applications to execute Git operations from JavaScript. Prior to 4.0.0, the default blockUnsafeOperationsPlugin compares parsed option names with literal dangerous option spellings while Git accepts unambiguous long-option abbreviations. Attacker-influenced push arguments such as abbreviated --receive-pack or --exec forms can therefore bypass detectVulnerableFlags, reach git push against a local or file remote or an attacker-influenced receive-pack target, and cause Git to invoke an attacker-selected command in consumers that expose those arguments. The clone-side abbreviation handling does not protect the push path. This issue is fixed in 4.0.0.

Source published

29 Sep 2026 18:39:57 UTC

Source modified

2 Oct 2026 12:21:16 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

simple-git, an interface for running git commands in any node.js application, enables applications to execute Git operations from JavaScript. Prior to 4.0.0, the default blockUnsafeOperationsPlugin compares parsed option names with literal dangerous option spellings while Git accepts unambiguous long-option abbreviations. Attacker-influenced push arguments such as abbreviated --receive-pack or --exec forms can therefore bypass detectVulnerableFlags, reach git push against a local or file remote or an attacker-influenced receive-pack target, and cause Git to invoke an attacker-selected command in consumers that expose those arguments. The clone-side abbreviation handling does not protect the push path. This issue is fixed in 4.0.0.

Source published

Sep 29, 2026, 6:39:57 PM (timezone not stated)

Source modified

Oct 2, 2026, 12:21:16 PM (timezone not stated)

Observed here

9 Nov 2026 05:03:50 UTC

Source terms

ENISA EUVD · source terms and attribution apply

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

simple-git, an interface for running git commands in any node.js application, enables applications to execute Git operations from JavaScript. Prior to 4.0.0, the default blockUnsafeOperationsPlugin compares parsed option names with literal dangerous option spellings while Git accepts unambiguous long-option abbreviations. Attacker-influenced push arguments such as abbreviated --receive-pack or --exec forms can therefore bypass detectVulnerableFlags, reach git push against a local or file remote or an attacker-influenced receive-pack target, and cause Git to invoke an attacker-selected command in consumers that expose those arguments. The clone-side abbreviation handling does not protect the push path. This issue is fixed in 4.0.0.

Source published

29 Sep 2026 19:17:25 UTC

Source modified

8 Oct 2026 20:11:17 UTC

Observed here

25 Oct 2026 04:17:26 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS 3.1 · [email protected] · Primary · 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

simple-git's blockUnsafeOperationsPlugin blocks dangerous git options (--upload-pack/--receive-pack/--exec/...) unless the consumer opts in via unsafe:{allowUnsafePack:true}. Detection (@simple-git/argv-parser detectVulnerableFlags) matches the parsed flag NAME against literal-spelling patterns: /--(upload|receive)-pack/ (requires the literal '-pack') and the string '--exec'. But git accepts unambiguous prefix abbreviations of long options, and expandToken (token-expander.ts) returns the LITERAL token as flag.name (it uses the spec only for needsNext, never to canonicalize). So `git push --receive-p=<cmd>` parses with flag.name='--receive-p', which /--(upload|receive)-pack/ does NOT match, yet git expands --receive-p -> --receive-pack and runs <cmd> (on a local/file remote, locally). The clone side is robust (its '--u' substring rule catches every --upload* abbreviation); the push --receive-* and --exe* abbreviations have no equivalent rule and slip through. Proof of concept (latest: simple-git 3.36.0, @simple-git/argv-parser 1.1.1, default unsafe plugin ON): Gate vulnerabilityCheck: 'push --receive-pack=touch...' -> BLOCKED; 'push --receive-pa=touch...' and 'push --receive-p=touch...' -> BYPASS (empty vulns); '--exec=' BLOCKED, '--exe=' BYPASS. End-to-end via simpleGit().push(): CONTROL git.push(['../bare','HEAD:refs/heads/c','--receive-pack=touch /tmp/pwned_ctrl;']) -> throws GitPluginError 'Use of --upload-pack or --receive-pack is not permitted...'; no command runs. BYPASS git.push(['../bare','HEAD:refs/heads/e2e','--receive-p=touch /tmp/pwned_e2e;']) -> NO GitPluginError; /tmp/pwned_e2e CREATED (git executed the injected command); only a later GitError surfaces. Direct git confirms `git push ../bare --receive-p='touch X;' HEAD:refs/heads/m` and `--exe='touch Y;'` both execute on a local/path remote. Impact: any app relying on simple-git's default unsafe-operations protection while passing attacker-influenced options/args into a git push (local/file remote, or attacker-influenced receive-pack target) can be made to execute arbitrary commands -- the exact protection CVE-2026-28291 provided, defeated by an abbreviated spelling. Same class/impact as GHSA-jcxm-m3jx-f287, on the push path. Remediation: canonicalize git option abbreviations before matching (resolve to the canonical long name via the per-task flag spec in expandToken), or match on the option stem/prefix down to the shortest unambiguous form for push receive-pack/exec (mirroring the clone-side '--u' approach). Also audit --template and -c/config-write detection for the same abbreviation gap. Credit: anir0y (independent security research).

Source published

5 Oct 2026 23:47:58 UTC

Source modified

6 Oct 2026 00:00:10 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Publisher rating · HIGH