GHSA-7J5W-7R7X-9V27
Vulnerability from github – Published: 2026-09-04 18:02 – Updated: 2026-09-04 18:02Maintainer resolution
The CodeWhale maintainers validated this report. The affected package ranges are recorded in the advisory metadata. Version 0.8.64 contains the fix in commit 9a34b5034d29f05d1f28fa61b04719ca6a741020. Users should upgrade to 0.8.64 or later. The original reporter analysis is preserved below.
Argument Injection in git_show Tool Allows Arbitrary File Write Without Approval
Overview
The git_show tool in DeepSeek-TUI executes git show with the model-supplied rev parameter passed unvalidated into the argv. git show honours the --output=<path> option, so a rev value beginning with --output= is interpreted as a flag rather than a revision. The tool is registered with ApprovalRequirement::Auto and declares ToolCapability::ReadOnly, so the write happens without a user prompt and contradicts the capability the catalog advertises to the model and the user.
This is the same vulnerability class as GHSA-72w5-pf8h-xfp4 (CVE-2026-45374): an auto-approved tool produces an effect outside the boundary the user consented to.
Impact
A malicious repository combined with prompt injection, the threat model already documented in CVE-2026-45311 (auto-loaded AGENTS.md is treated as instructions by the model) yields an unprompted arbitrary file write at the privilege of the user running DeepSeek-TUI.
Useful targets reachable as the invoking user:
~/.ssh/authorized_keys~/.bashrc,~/.zshrc,~/.profile~/.gitconfig(chainable into RCE viacore.editor)~/.config/**,~/.aws/credentials, project source files
The written content is the git show rendering of HEAD commit hash, author/date header, indented commit message, and (when patch=true) diff hunks. The commit subject, body, author identity, and diff text are entirely attacker-controlled because the attacker owns the repository HEAD. The leading commit <hash> line prevents clean overwrite of formats that reject unknown tokens, but is silently ignorable in files parsed as comments-or-text (crontab, dotfiles consumed by tolerant readers) and is irrelevant for the destructive/DoS sub-case (clobbering ~/.ssh/authorized_keys locks the user out; clobbering a project file corrupts source).
Technical Details
Root Cause
crates/tui/src/tools/git_history.rs:
// L196-198
fn approval_requirement(&self) -> ApprovalRequirement {
ApprovalRequirement::Auto
}
// L204-228 (excerpt)
async fn execute(&self, input: Value, context: &ToolContext) -> Result<ToolResult, ToolError> {
let rev = required_str(&input, "rev")?;
...
let mut args = vec![
"show".to_string(),
"--no-color".to_string(),
"--no-ext-diff".to_string(),
];
if patch { args.push(format!("--unified={unified}")); }
else { args.push("--no-patch".to_string()); }
if stat { args.push("--stat".to_string()); }
args.push(rev.to_string()); // unvalidated, no `--end-of-options` sentinel
...
}
The JSON schema for rev is {"type": "string"} (L161-164) with no pattern, no enum, and no length cap. required_str performs no semantic validation. The argv has no --end-of-options separator between the trailing options and rev, so git's option parser keeps consuming flags from rev.
The same pattern in git_blame (L322-388) is tracked in a separate advisory.
Why --output Works
git show shares its option parser with git log / git diff, which expose --output=<file>. The implementation opens the path with O_WRONLY | O_CREAT | O_TRUNC and writes the formatted output there. No permission check beyond the filesystem's own running as the user is sufficient to clobber anything the user owns.
Proof of Concept
The vulnerable argv assembled by the tool when invoked with
{"rev": "--output=/home/victim/.bashrc"} is equivalent to:
git show --no-color --no-ext-diff --no-patch --stat --output=/home/victim/.bashrc
Reproduced against system git as a non-root user:
$ id
uid=1001(lowtest) gid=1001(lowtest) groups=1001(lowtest)
$ cd /tmp/lp && git init -q
$ echo a > a.txt && git add a.txt
$ git -c user.email=a@b -c user.name=a commit -q -m "lol"
$ git show --no-color --no-patch "--output=/home/lowtest/.bashrc_clobbered" HEAD
$ ls -la /home/lowtest/.bashrc_clobbered
-rw-rw-r-- 1 lowtest lowtest 128 May 19 07:05 /home/lowtest/.bashrc_clobbered
End-to-end exploitation path:
- Attacker publishes a repository whose
AGENTS.mdinstructs the model to callgit_showwithrevset to a crafted--output=string targeting a file in the victim's home directory. The same auto-load pathway documented in CVE-2026-45311 applies. - Victim opens the repository in DeepSeek-TUI and issues any prompt that exercises the agent loop.
- The model issues the tool call. Because
approval_requirement()returnsAuto, no approval UI is shown. git show --output=<path>overwrites the target file with attacker-controlled commit metadata and diff text.
Remediation
Two changes in crates/tui/src/tools/git_history.rs:
Insert an end-of-options sentinel before rev so git stops parsing flags:
rust
args.push("--end-of-options".to_string());
args.push(rev.to_string());
Reject rev values that begin with - (or restrict to a revision-shape
regex ^[A-Za-z0-9._/^~@:{}-]+$ after the leading character check):
rust
if rev.starts_with('-') {
return Err(ToolError::invalid_input("rev must not start with '-'"));
}
A regression test mirroring run_tests_requires_user_approval (test_runner.rs:197) should assert that rev = "--output=/tmp/x" is rejected.
{
"affected": [
{
"package": {
"ecosystem": "crates.io",
"name": "deepseek-tui"
},
"ranges": [
{
"events": [
{
"introduced": "0.3.27"
},
{
"last_affected": "0.8.41"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "deepseek-tui"
},
"ranges": [
{
"events": [
{
"introduced": "0.3.27"
},
{
"fixed": "0.8.41"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "crates.io",
"name": "codewhale-tui"
},
"ranges": [
{
"events": [
{
"introduced": "0.8.41"
},
{
"fixed": "0.8.64"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "codewhale"
},
"ranges": [
{
"events": [
{
"introduced": "0.8.41"
},
{
"fixed": "0.8.64"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-75913"
],
"database_specific": {
"cwe_ids": [
"CWE-73",
"CWE-88"
],
"github_reviewed": true,
"github_reviewed_at": "2026-09-04T18:02:37Z",
"nvd_published_at": "2026-08-18T16:18:23Z",
"severity": "HIGH"
},
"details": "### Maintainer resolution\n\nThe CodeWhale maintainers validated this report. The affected package ranges are recorded in the advisory metadata. Version 0.8.64 contains the fix in commit 9a34b5034d29f05d1f28fa61b04719ca6a741020. Users should upgrade to 0.8.64 or later. The original reporter analysis is preserved below.\n\n# Argument Injection in `git_show` Tool Allows Arbitrary File Write Without Approval\n\n## Overview\n\nThe `git_show` tool in DeepSeek-TUI executes `git show` with the model-supplied `rev` parameter passed unvalidated into the argv. `git show` honours the `--output=\u003cpath\u003e` option, so a `rev` value beginning with `--output=` is interpreted as a flag rather than a revision. The tool is registered with `ApprovalRequirement::Auto` and declares `ToolCapability::ReadOnly`, so the write happens without a user prompt and contradicts the capability the catalog advertises to the model and the user.\n\nThis is the same vulnerability class as GHSA-72w5-pf8h-xfp4 (CVE-2026-45374): an auto-approved tool produces an effect outside the boundary the user consented to.\n\n## Impact\n\nA malicious repository combined with prompt injection, the threat model already documented in CVE-2026-45311 (auto-loaded `AGENTS.md` is treated as instructions by the model) yields an unprompted arbitrary file write at the privilege of the user running DeepSeek-TUI.\n\nUseful targets reachable as the invoking user:\n\n- `~/.ssh/authorized_keys`\n- `~/.bashrc`, `~/.zshrc`, `~/.profile`\n- `~/.gitconfig` (chainable into RCE via `core.editor`)\n- `~/.config/**`, `~/.aws/credentials`, project source files\n\nThe written content is the `git show` rendering of HEAD commit hash, author/date header, indented commit message, and (when `patch=true`) diff hunks. The commit subject, body, author identity, and diff text are entirely attacker-controlled because the attacker owns the repository HEAD. The leading `commit \u003chash\u003e` line prevents clean overwrite of formats that reject unknown tokens, but is silently ignorable in files parsed as comments-or-text (crontab, dotfiles consumed by tolerant readers) and is irrelevant for the destructive/DoS sub-case (clobbering `~/.ssh/authorized_keys` locks the user out; clobbering a project file corrupts source).\n\n## Technical Details\n\n### Root Cause\n\n`crates/tui/src/tools/git_history.rs`:\n\n```rust\n// L196-198\nfn approval_requirement(\u0026self) -\u003e ApprovalRequirement {\n ApprovalRequirement::Auto\n}\n\n// L204-228 (excerpt)\nasync fn execute(\u0026self, input: Value, context: \u0026ToolContext) -\u003e Result\u003cToolResult, ToolError\u003e {\n let rev = required_str(\u0026input, \"rev\")?;\n ...\n let mut args = vec![\n \"show\".to_string(),\n \"--no-color\".to_string(),\n \"--no-ext-diff\".to_string(),\n ];\n if patch { args.push(format!(\"--unified={unified}\")); }\n else { args.push(\"--no-patch\".to_string()); }\n if stat { args.push(\"--stat\".to_string()); }\n args.push(rev.to_string()); // unvalidated, no `--end-of-options` sentinel\n ...\n}\n```\n\nThe JSON schema for `rev` is `{\"type\": \"string\"}` (L161-164) with no `pattern`, no enum, and no length cap. `required_str` performs no semantic validation. The argv has no `--end-of-options` separator between the trailing options and `rev`, so git\u0027s option parser keeps consuming flags from `rev`.\n\nThe same pattern in `git_blame` (L322-388) is tracked in a separate advisory.\n\n### Why `--output` Works\n\n`git show` shares its option parser with `git log` / `git diff`, which expose `--output=\u003cfile\u003e`. The implementation opens the path with `O_WRONLY | O_CREAT | O_TRUNC` and writes the formatted output there. No permission check beyond the filesystem\u0027s own running as the user is sufficient to clobber anything the user owns.\n\n## Proof of Concept\n\nThe vulnerable argv assembled by the tool when invoked with\n`{\"rev\": \"--output=/home/victim/.bashrc\"}` is equivalent to:\n\n```\ngit show --no-color --no-ext-diff --no-patch --stat --output=/home/victim/.bashrc\n```\n\nReproduced against system `git` as a non-root user:\n\n```\n$ id\nuid=1001(lowtest) gid=1001(lowtest) groups=1001(lowtest)\n\n$ cd /tmp/lp \u0026\u0026 git init -q\n$ echo a \u003e a.txt \u0026\u0026 git add a.txt\n$ git -c user.email=a@b -c user.name=a commit -q -m \"lol\"\n\n$ git show --no-color --no-patch \"--output=/home/lowtest/.bashrc_clobbered\" HEAD\n$ ls -la /home/lowtest/.bashrc_clobbered\n-rw-rw-r-- 1 lowtest lowtest 128 May 19 07:05 /home/lowtest/.bashrc_clobbered\n```\n\nEnd-to-end exploitation path:\n\n- Attacker publishes a repository whose `AGENTS.md` instructs the model to call `git_show` with `rev` set to a crafted `--output=` string targeting a file in the victim\u0027s home directory. The same auto-load pathway documented in CVE-2026-45311 applies.\n- Victim opens the repository in DeepSeek-TUI and issues any prompt that exercises the agent loop.\n- The model issues the tool call. Because `approval_requirement()` returns `Auto`, no approval UI is shown.\n- `git show --output=\u003cpath\u003e` overwrites the target file with attacker-controlled commit metadata and diff text.\n\n## Remediation\n\nTwo changes in `crates/tui/src/tools/git_history.rs`:\n\nInsert an end-of-options sentinel before `rev` so git stops parsing flags:\n\n ```rust\n args.push(\"--end-of-options\".to_string());\n args.push(rev.to_string());\n ```\n\nReject `rev` values that begin with `-` (or restrict to a revision-shape\n regex `^[A-Za-z0-9._/^~@:{}-]+$` after the leading character check):\n\n ```rust\n if rev.starts_with(\u0027-\u0027) {\n return Err(ToolError::invalid_input(\"rev must not start with \u0027-\u0027\"));\n }\n ```\n\nA regression test mirroring `run_tests_requires_user_approval` (`test_runner.rs:197`) should assert that `rev = \"--output=/tmp/x\"` is rejected.",
"id": "GHSA-7j5w-7r7x-9v27",
"modified": "2026-09-04T18:02:37Z",
"published": "2026-09-04T18:02:37Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/Hmbown/CodeWhale/security/advisories/GHSA-7j5w-7r7x-9v27"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-75913"
},
{
"type": "WEB",
"url": "https://github.com/Hmbown/CodeWhale/commit/9a34b5034d29f05d1f28fa61b04719ca6a741020"
},
{
"type": "PACKAGE",
"url": "https://github.com/Hmbown/CodeWhale"
},
{
"type": "WEB",
"url": "https://www.vulncheck.com/advisories/codewhale-before-argument-injection-via-git-show"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H",
"type": "CVSS_V4"
}
],
"summary": "CodeWhale: Argument Injection in `git_show` Tool Allows Arbitrary File Write Without Approval"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.