# CVE-2026-27704: Dart SDK and Flutter SDK have Zip slip in Dart Pub package extraction

> Attackers can exploit Zip slip in Dart/Flutter SDKs to write files outside the cache directory via malicious packages, requiring an upgrade to patched versions.

- **Severity:** Medium 6.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Feb 2026
- **Updated:** 25 Feb 2026
- **Also known as:** GHSA-q739-79rh-vmvp

## What is CVE-2026-27704?

CVE-2026-27704 is a medium-severity path traversal vulnerability in dart-lang flutter, published on 25 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Dart and Flutter SDKs provide software development kits for the Dart programming language. In versions of the Dart SDK prior to 3.11.0 and the Flutter SDK prior to version 3.41.0, when the pub client (`dart pub` and `flutter pub`) extracts a package in the pub cache, a malicious package archive can have files extracted outside the destination directory in the `PUB_CACHE`.  A fix has been landed in commit 26c6985c742593d081f8b58450f463a584a4203a. By normalizing the file path before writing file, the attacker can no longer traverse up via a symlink. This patch is released in Dart 3.11.0 and Flutter 3.41.0.vAll packages on pub.dev have been vetted for this vulnerability. New packages are no longer allowed to contain symlinks. The pub client itself doesn't upload symlinks, but duplicates the linked entry, and has been doing this for years. Those whose dependencies are all from pub.dev, third-party repositories trusted to not contain malicious code, or git dependencies are not affected by this vulnerability.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-27704?

It affects 2 products.


Products: Dart Dart Software Development Kit, Flutter Flutter.

## How do I fix CVE-2026-27704?

No fix has been published for CVE-2026-27704 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-27704 being exploited?

There is no known exploitation of CVE-2026-27704 in the wild and no public exploit code.

## Other vulnerabilities in dart-lang flutter

- [CVE-2022-3095](https://insights.sbomify.com/CVE-2022-3095/): Incorrect parsing of the backslash characters in Dart library (critical 9.8)
- [CVE-2021-22568](https://insights.sbomify.com/CVE-2021-22568/): Dart - Publishing to third-party package repositories may expose pub.dev credentials (high 8.8)
- [CVE-2022-0451](https://insights.sbomify.com/CVE-2022-0451/): Auth bypass in Dark SDK (medium 6.5)
- [CVE-2021-22540](https://insights.sbomify.com/CVE-2021-22540/): XSS in Dart SDK (medium 6.1)
- [CVE-2020-8923](https://insights.sbomify.com/CVE-2020-8923/): XSS in Dart (medium 5.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-27704 and fix it if it is affected.

What it is: CVE-2026-27704 is a medium-severity path traversal vulnerability in dart-lang flutter, published on 25 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-27704 in the wild and no public exploit code.

Affected product: dart-lang flutter. 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-2026-27704/ (Markdown: https://insights.sbomify.com/CVE-2026-27704/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-27704
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-27704
- OSV: https://osv.dev/vulnerability/CVE-2026-27704

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-27704/
Summaries are generated and may contain mistakes; the official description above is the record.