How severe is GHSA-49w6-73cw-chjr?

No CVSS score has been assigned to GHSA-49w6-73cw-chjr yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-49w6-73cw-chjr?

GHSA-49w6-73cw-chjr affects the following packages: astro (npm), astro (npm). Ecosystems affected: npm.

How do I fix GHSA-49w6-73cw-chjr?

Update astro to 5.0.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-49w6-73cw-chjr is resolved across your whole dependency graph.

How do I detect GHSA-49w6-73cw-chjr in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for astro. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-49w6-73cw-chjr if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-49w6-73cw-chjr?

O3 pinpoints whether GHSA-49w6-73cw-chjr is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-49w6-73cw-chjr actively exploited in the wild?

No public exploit code has been indexed for GHSA-49w6-73cw-chjr 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 GHSA-49w6-73cw-chjr?

GHSA-49w6-73cw-chjr has an EPSS (Exploit Prediction Scoring System) score of 1.5%, placing it in the 70th 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 GHSA-49w6-73cw-chjr?

GHSA-49w6-73cw-chjr is classified as CWE-219 (CWE-219). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Is there exploit tooling available for GHSA-49w6-73cw-chjr?

A Nuclei detection template exists for GHSA-49w6-73cw-chjr, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was GHSA-49w6-73cw-chjr published, and has it been updated?

GHSA-49w6-73cw-chjr was published on December 19, 2024 and was last updated on November 27, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

GHSA-49w6-73cw-chjr

Astro's server source code is exposed to the public if sourcemaps are enabled

Also known asCVE-2024-56159

Published

Dec 19, 2024

Updated

Nov 27, 2025

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

1.5%probability of exploitation in next 30 days

Lower Risk70th percentile-9.32%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

2 pkgs affected

📦astro📦astro

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

Description

Summary

A bug in the build process allows any unauthenticated user to read parts of the server source code.

Details

During build, along with client assets such as css and font files, the sourcemap files for the server code are moved to a publicly-accessible folder. https://github.com/withastro/astro/blob/176fe9f113fd912f9b61e848b00bbcfecd6d5c2c/packages/astro/src/core/build/static-build.ts#L139

Any outside party can read them with an unauthorized HTTP GET request to the same server hosting the rest of the website.

While some server files are hashed, making their access obscure, the files corresponding to the file system router (those in src/pages) are predictably named. For example. the sourcemap file for src/pages/index.astro gets named dist/client/pages/index.astro.mjs.map.

PoC

Here is one example of an affected open-source website: https://creatorsgarten.org/pages/index.astro.mjs.map

The file can be saved and opened using https://evanw.github.io/source-map-visualization/ to reconstruct the source code.

The above accurately mirrors the source code as seen in the repository: https://github.com/creatorsgarten/creatorsgarten.org/blob/main/src/pages/index.astro

The above was found as the 4th result (and the first one on Astro 5.0+) when making the following search query on GitHub.com (search results link):

path:astro.config.mjs @sentry/astro

This vulnerability is the root cause of https://github.com/withastro/astro/issues/12703, which links to a simple stackblitz project demonstrating the vulnerability. Upon build, notice the contents of the dist/client (referred to as config.build.client in astro code) folder. All astro servers make the folder in question accessible to the public internet without any authentication. It contains .map files corresponding to the code that runs on the server.

Impact

All server-output (SSR) projects on Astro 5 versions v5.0.3 through v5.0.6 (inclusive), that have sourcemaps enabled, either directly or through an add-on such as sentry, are affected. The fix for server-output projects was released in [email protected].

Additionally, all static-output (SSG) projects built using Astro 4 versions 4.16.17 or older, or Astro 5 versions 5.0.7 or older, that have sourcemaps enabled are also affected. The fix for static-output projects was released in [email protected], and backported to Astro v4 in [email protected].

The immediate impact is limited to source code. Any secrets or environment variables are not exposed unless they are present verbatim in the source code.

There is no immediate loss of integrity within the the vulnerable server. However, it is possible to subsequently discover another vulnerability via the revealed source code .

There is no immediate impact to availability of the vulnerable server. However, the presence of an unsafe regular expression, for example, can quickly be exploited to subsequently compromise the availability.

Network attack vector.
Low attack complexity.
No privileges required.
No interaction required from an authorized user.
Scope is limited to first party. Although the source code of closed-source third-party software may also be exposed.

Remediation

The fix for server-output projects was released in [email protected], and the fix for static-output projects was released in [email protected] and backported to Astro v4 in [email protected]. Users are advised to update immediately if they are using sourcemaps or an integration that enables sourcemaps.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`astro`	≥ 5.0.0-alpha.0&&< 5.0.8	5.0.8
📦npm	`astro`	all versions	4.16.18

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for astro. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update astro to 5.0.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-49w6-73cw-chjr is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-49w6-73cw-chjr is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-49w6-73cw-chjr. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary A bug in the build process allows any unauthenticated user to read parts of the server source code. ### Details During build, along with client assets such as css and font files, the sourcemap files **for the server code** are moved to a publicly-accessible folder. https://github.com/withastro/astro/blob/176fe9f113fd912f9b61e848b00bbcfecd6d5c2c/packages/astro/src/core/build/static-build.ts#L139 Any outside party can read them with an unauthorized HTTP GET request to the same server hosting the rest of the website. While some server files are hashed, making their access obscure,

O3 Security · Impact-Aware SCA

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