# CVE-2023-26136: tough-cookie Prototype Pollution vulnerability

> Prototype pollution in tough-cookie allows attackers to manipulate object prototypes, potentially leading to code execution or privilege escalation.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Jul 2023
- **Updated:** 27 Aug 2025
- **Also known as:** AZL-43684, AZL-44556, CLEANSTART-2026-ZC18850, CLSA-2026-1773274553, CLSA-2026-1773274554, CLSA-2026-1773274558, CLSA-2026-1776818217, CLSA-2026-1792791719, DEBIAN-CVE-2023-26136, DLA-3488-1, GHSA-72xf-g2v4-qvf3, MGASA-2024-0080, MINI-353m-2c88-2935, MINI-67c3-m3v2-5jj9, OESA-2023-1930, OESA-2023-1952, ROOT-APP-NPM-CVE-2023-26136, UBUNTU-CVE-2023-26136

## What is CVE-2023-26136?

CVE-2023-26136 is a medium-severity vulnerability in tough-cookie, published on 1 Jul 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Versions of the package tough-cookie before 4.1.3 are vulnerable to Prototype Pollution due to improper handling of Cookies when using CookieJar in rejectPublicSuffixes=false mode. This issue arises from the manner in which the objects are initialized.

Weakness: CWE-1321 (Improperly Controlled Modification of Object Prototype Attributes)

## Which versions are affected by CVE-2023-26136?

2 open source packages ship an affected version, including tough-cookie. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `tough-cookie` | npm | All versions | 4.1.3 |
| `tough-cookie` | npm | All versions | 4.1.3 |

Products: Salesforce Tough-Cookie.

## How do I fix CVE-2023-26136?

Upgrade tough-cookie to 4.1.3 or later.

## Is CVE-2023-26136 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-26136 exists.

Public exploit code:

- Researching on the vulnrability CVE-2023-26136 (github_poc): https://github.com/CUCUMBERanOrSNCompany/SealSecurityAssignment
- Fix open source package uses tough-cookie 2.5.0 - CVE-2023-26136, (github_poc): https://github.com/ronmadar/Open-Source-Seal-Security
- Fix prototype pollution vulnerability (CVE-2023-26136) for tough-cookie package (github_poc): https://github.com/m-lito13/SealSecurity_Exam
- CVE-2023-26136 vulnerability research (github_poc): https://github.com/dani33339/Tough-Cookie-v2.5.0-Patched
- This repository contains a solution for the CVE-2023-26136 vulnerability. (github_poc): https://github.com/morrisel/CVE-2023-26136
- ecurity patch for CVE-2023-26136 in tough-cookie 2.5.0 - Prototype pollution vulnerability fix with backward compatibility (github_poc): https://github.com/uriyahav/tough-cookie-2.5.0-cve-2023-26136-fix

## Other vulnerabilities in tough-cookie

- [CVE-2017-15010](https://insights.sbomify.com/CVE-2017-15010/): Regular Expression Denial of Service in tough-cookie (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-26136 and fix it if it is affected.

What it is: CVE-2023-26136 is a medium-severity vulnerability in tough-cookie, published on 1 Jul 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-26136 exists.

Affected packages and fixed versions:
- tough-cookie (npm): affected all versions; fixed in 4.1.3
- tough-cookie (npm): affected all versions; fixed in 4.1.3

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-26136/ (Markdown: https://insights.sbomify.com/CVE-2023-26136/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-26136
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-26136
- OSV: https://osv.dev/vulnerability/CVE-2023-26136

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-26136/
Summaries are generated and may contain mistakes; the official description above is the record.