# CVE-2021-46477: Memory corruption in n/a

> A heap buffer overflow in the Jsish JavaScript engine allows attackers to cause a denial of service via crafted regular expressions.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 25 Jan 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-wv49-q2r3-4933

## What is CVE-2021-46477?

CVE-2021-46477 is a medium-severity memory corruption vulnerability in Jsish Jsish, published on 25 Jan 2022. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Jsish v3.5.0 was discovered to contain a heap buffer overflow via RegExp_constructor in src/jsiRegexp.c. This vulnerability can lead to a Denial of Service (DoS).

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2021-46477?

It affects 1 product.


Products: Jsish Jsish.

## How do I fix CVE-2021-46477?

No fix has been published for CVE-2021-46477 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-46477 being exploited?

There is no known exploitation of CVE-2021-46477 in the wild and no public exploit code.

## Other vulnerabilities in Jsish Jsish

- [CVE-2025-65570](https://insights.sbomify.com/CVE-2025-65570/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-24186](https://insights.sbomify.com/CVE-2024-24186/): Denial of service in n/a (critical 9.8)
- [CVE-2024-24188](https://insights.sbomify.com/CVE-2024-24188/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-24189](https://insights.sbomify.com/CVE-2024-24189/): Use after free in n/a (critical 9.8)
- [CVE-2020-22873](https://insights.sbomify.com/CVE-2020-22873/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-46477 and fix it if it is affected.

What it is: CVE-2021-46477 is a medium-severity memory corruption vulnerability in Jsish Jsish, published on 25 Jan 2022. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-46477 in the wild and no public exploit code.

Affected product: Jsish Jsish. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2021-46477/ (Markdown: https://insights.sbomify.com/CVE-2021-46477/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-46477
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-46477
- OSV: https://osv.dev/vulnerability/CVE-2021-46477

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-46477/
Summaries are generated and may contain mistakes; the official description above is the record.