How severe is CVE-2021-3148?

CVE-2021-3148 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-3148?

CVE-2021-3148 affects the following packages: salt (PyPI), salt (PyPI), salt (PyPI), salt (PyPI), salt (PyPI), salt (PyPI), salt (PyPI), salt (PyPI), and 1 more. Ecosystems affected: PyPI.

How do I fix CVE-2021-3148?

Update salt to 2015.8.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-3148 is resolved across your whole dependency graph.

How do I detect CVE-2021-3148 in my PyPI dependencies?

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

How do I mitigate CVE-2021-3148 if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is CVE-2021-3148 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-3148 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 CVE-2021-3148?

CVE-2021-3148 has an EPSS (Exploit Prediction Scoring System) score of 8.2%, placing it in the 95th 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 CVE-2021-3148?

CVE-2021-3148 is classified as CWE-77 (CWE-77). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-3148 published, and has it been updated?

CVE-2021-3148 was published on February 27, 2021 and was last updated on October 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

CRITICAL severity

CVE-2021-3148 — salt

CRITICAL

CVE-2021-3148 is a critical-severity (CVSS 9.8) CWE-77 vulnerability in salt. A fix is available for salt — see the affected versions and patch details below.

SaltStack Salt command injection in the Salt-API when using the Salt-SSH client

Also known asGHSA-ghc2-hx3w-jqmpPYSEC-2021-55

Published

Feb 27, 2021

Updated

Oct 20, 2026

Affected

9 pkgs

Patched

8 / 9

Exploits

None indexed

Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

8.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs95th percentile — riskier than 95% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

9 pkgs affected

🐍salt🐍salt🐍salt🐍salt🐍salt🐍salt🐍salt🐍salt+1 more

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

An issue was discovered in SaltStack Salt before 3002.5. Sending crafted web requests to the Salt API can result in salt.utils.thin.gen_thin() command injection because of different handling of single versus double quotes. This is related to salt/utils/thin.py.

Affected Packages

9 total 8 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`salt`	all versions	2015.8.13`pip install --upgrade 'salt==2015.8.13'`
🐍PyPI	`salt`	≥ 2016.3.0&&< 2016.11.5	2016.11.5`pip install --upgrade 'salt==2016.11.5'`
🐍PyPI	`salt`	≥ 2016.11.7&&< 2016.11.10	2016.11.10`pip install --upgrade 'salt==2016.11.10'`
🐍PyPI	`salt`	≥ 2017.5.0&&< 2017.7.8	2017.7.8`pip install --upgrade 'salt==2017.7.8'`
🐍PyPI	`salt`	≥ 2018.2.0	No fix
🐍PyPI	`salt`	≥ 2019.2.0&&< 2019.2.8	2019.2.8`pip install --upgrade 'salt==2019.2.8'`

Affected Products

3 products · 21 configurations

debian linuxdebian

3 versions

9.010.011.0

fedorafedoraproject

3 versions

323334

Application

saltsaltstack

≥ 3002 && ≤ 2018.3.5

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for salt, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update salt to 2015.8.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-3148 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2021-3148 in your dependencies?

Find it across PyPI, including transitive dependencies.

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