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Response snapshot Oct 31, 2026, 18:21 UTC

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VulnerabilityCVE-2026-102827

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

simple-git's blockUnsafeOperationsPlugin blocks dangerous git options (--upload-pack/--receive-pack/--exec/...) unless the consumer opts in via unsafe:{allowUnsafePack:true}.

At a glance

Exploited
Not known
Severity
8.1 High (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

GitHub lists first patched versions: simple-git: 4.0.0. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-858h-whjf-mvg5 (opens a new tab)

What happened

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= parses with flag.name='--receive-p', which /--(upload|receive)-pack/ does NOT match, yet git expands --receive-p -> --receive-pack and runs (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(['..

Continue reading

/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).

Affected package ranges reported by GitHub: simple-git: <= 3.36.0

Scores and how they were measured

CVSS base severity

8.1

Version 3.1As of

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

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-858h-whjf-mvg5 (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-858h-whjf-mvg5, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 31). simple-git: unsafe-operations plugin bypass via git long-option abbreviation (--receive-p/--exe) -> command execution (residual of CVE-2026-28291) (CVE-2026-102827). https://kevwire.com/record/CVE-2026-102827

MLA

"simple-git: unsafe-operations plugin bypass via git long-option abbreviation (--receive-p/--exe) -> command execution (residual of CVE-2026-28291) (CVE-2026-102827)." KEVWire, 31 Oct. 2026, kevwire.com/record/CVE-2026-102827.

Chicago

KEVWire. "simple-git: unsafe-operations plugin bypass via git long-option abbreviation (--receive-p/--exe) -> command execution (residual of CVE-2026-28291) (CVE-2026-102827)." Last modified October 31, 2026. https://kevwire.com/record/CVE-2026-102827.

Evidence summary (plain text)

simple-git: unsafe-operations plugin bypass via git long-option abbreviation (--receive-p/--exe) -> command execution (residual of CVE-2026-28291) (Oct 5, 2026).
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).
CVSS 8.1 (version 3.1; evidence as of Oct 31, 2026; https://github.com/advisories/GHSA-858h-whjf-mvg5).
Sources:
GitHub-reviewed advisory GHSA-858h-whjf-mvg5: https://github.com/advisories/GHSA-858h-whjf-mvg5
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc
Record ID: CVE-2026-102827.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 31, 2026, 18:05 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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