CVE-2021-21353
Remote code execution in pug
Pug is an npm package which is a high-performance template engine. In pug before version 3.0.1, if a remote attacker was able to control the pretty option of the pug compiler, e.g. if you spread a user provided object such as the query parameters of a request into the pug template inputs, it was possible for them to achieve remote code execution on the node.js backend. This is fixed in version 3.0.1. This advisory applies to multiple pug packages including "pug", "pug-code-gen". pug-code-gen has a backported fix at version 2.0.3. This advisory is not exploitable if there is no way for un-trusted input to be passed to pug as the pretty option, e.g. if you compile templates in advance before applying user input to them, you do not need to upgrade.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Remote code execution in pug
Pug is an npm package which is a high-performance template engine. In pug before version 3.0.1, if a remote attacker was able to control the pretty option of the pug compiler, e.g. if you spread a user provided object such as the query parameters of a request into the pug template inputs, it was possible for them to achieve remote code execution on the node.js backend. This is fixed in version 3.0.1. This advisory applies to multiple pug packages including "pug", "pug-code-gen". pug-code-gen has a backported fix at version 2.0.3. This advisory is not exploitable if there is no way for un-trusted input to be passed to pug as the pretty option, e.g. if you compile templates in advance before applying user input to them, you do not need to upgrade.
- Record
CVE-2021-21353- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N - Weakness
- CWE-74
- Updated
- 2026-11-02
EUVDEUVD-2021-0685
Pug is an npm package which is a high-performance template engine. In pug before version 3.0.1, if a remote attacker was able to control the pretty option of the pug compiler, e.g. if you spread a user provided object such as the query parameters of a request into the pug template inputs, it was possible for them to achieve remote code execution on the node.js backend. This is fixed in version 3.0.1. This advisory applies to multiple pug packages including "pug", "pug-code-gen". pug-code-gen has a backported fix at version 2.0.3. This advisory is not exploitable if there is no way for un-trusted input to be passed to pug as the pretty option, e.g. if you compile templates in advance before applying user input to them, you do not need to upgrade.
- Record
EUVD-2021-0685- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-p493-635q-r6gr
Remote code execution via the `pretty` option.
Impact
If a remote attacker was able to control the pretty option of the pug compiler, e.g. if you spread a user provided object such as the query parameters of a request into the pug template inputs, it was possible for them to achieve remote code execution on the node.js backend.
Patches
Upgrade to [email protected] or [email protected] or [email protected], which correctly sanitise the parameter.
Workarounds
If there is no way for un-trusted input to be passed to pug as the pretty option, e.g. if you compile templates in advance before applying user input to them, you do not need to upgrade.
References
Original report: https://github.com/pugjs/pug/issues/3312
For more information
If you believe you have found other vulnerabilities, please DO NOT open an issue. Instead, you can follow the instructions in our Security Policy
- Record
GHSA-p493-635q-r6gr- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N - Weakness
- CWE-74, CWE-94
- Updated
- 2026-11-02
NVD
Pug is an npm package which is a high-performance template engine. In pug before version 3.0.1, if a remote attacker was able to control the pretty option of the pug compiler, e.g. if you spread a user provided object such as the query parameters of a request into the pug template inputs, it was possible for them to achieve remote code execution on the node.js backend. This is fixed in version 3.0.1. This advisory applies to multiple pug packages including "pug", "pug-code-gen". pug-code-gen has a backported fix at version 2.0.3. This advisory is not exploitable if there is no way for un-trusted input to be passed to pug as the pretty option, e.g. if you compile templates in advance before applying user input to them, you do not need to upgrade.
- Record
CVE-2021-21353- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N - CVSS 3.1
- 9.0 Critical
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H - CVSS 2.0
- 6.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:P - Weakness
- CWE-74, CWE-94
- Updated
- 2026-11-02
OSV
Pug is an npm package which is a high-performance template engine. In pug before version 3.0.1, if a remote attacker was able to control the pretty option of the pug compiler, e.g. if you spread a user provided object such as the query parameters of a request into the pug template inputs, it was possible for them to achieve remote code execution on the node.js backend. This is fixed in version 3.0.1. This advisory applies to multiple pug packages including "pug", "pug-code-gen". pug-code-gen has a backported fix at version 2.0.3. This advisory is not exploitable if there is no way for un-trusted input to be passed to pug as the pretty option, e.g. if you compile templates in advance before applying user input to them, you do not need to upgrade.
- Record
CVE-2021-21353- CVSS 3.1
- 9.0 Critical
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-04
OSVGHSA-p493-635q-r6gr
Remote code execution via the `pretty` option.
Impact
If a remote attacker was able to control the pretty option of the pug compiler, e.g. if you spread a user provided object such as the query parameters of a request into the pug template inputs, it was possible for them to achieve remote code execution on the node.js backend.
Patches
Upgrade to [email protected] or [email protected] or [email protected], which correctly sanitise the parameter.
Workarounds
If there is no way for un-trusted input to be passed to pug as the pretty option, e.g. if you compile templates in advance before applying user input to them, you do not need to upgrade.
References
Original report: https://github.com/pugjs/pug/issues/3312
For more information
If you believe you have found other vulnerabilities, please DO NOT open an issue. Instead, you can follow the instructions in our Security Policy
- Record
GHSA-p493-635q-r6gr- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N - Weakness
- CWE-74, CWE-94
- Updated
- 2026-11-02
OSVCLSA-2026-1777250300 No score
TuxCare security update for pug (2 CVEs)
TuxCare rebuilt pug to address 2 CVEs. Fixed in 2.0.4-tuxcare.4.
- Record
CLSA-2026-1777250300- Updated
- 2026-11-02
OSVROOT-APP-NPM-CVE-2021-21353 No score
CVE-2021-21353 in pug - Patched by Root
Root has patched CVE-2021-21353 in the pug package for Root:npm. Multiple fixed versions available.
- Record
ROOT-APP-NPM-CVE-2021-21353- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
pugnpm |
before 3.0.1 | 3.0.1 |
pug-code-gennpm |
before 2.0.3 | 2.0.3 |
pug-code-gennpm |
3.0.0 up to 3.0.2 | 3.0.2 |
pugTuxCare:npm From an advisory covering 2 CVEs |
2.0.4-tuxcare.0 up to 2.0.4-tuxcare.4, plus listed versions 2.0.42.0.4-tuxcare.12.0.4-tuxcare.22.0.4-tuxcare.3 |
2.0.4-tuxcare.4 |
pugRoot:npm |
before 2.0.4-aikido.2 | 2.0.4-aikido.2 |
pug-code-genRoot:npm |
before 2.0.2-aikido.1 | 2.0.2-aikido.1 |
@rootio/pugRoot:npm |
before 2.0.4-root.io.2 | 2.0.4-root.io.2 |
@rootio/pug-code-genRoot:npm |
before 2.0.2-root.io.1 | 2.0.2-root.io.1 |
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | jinsu9758/PUG-RCE-CVE-2021-21353-POC | 2025-03-29 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected | ||
| facts | OSV | |
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-21353 is a medium vulnerability (CVSS 6.8) in Pugjs Pug, published March 3, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 4.27%, the 91st percentile. Fixed in pug 3.0.1.
References
github.com/pugjs/pug/security/advisories/GHSA-p493-635q-r6gr
npmjs.com/package/pug
nvd.nist.gov/vuln/detail/CVE-2021-21353