Vulnerabilities

Vulnerability · CVE-2026-27729

Astro is a web framework.

Published Feb 24, 2026 · catalog updated Jun 17, 2026 · Astro is a web

Check if you run it

No confirmed exploitation is on record for CVE-2026-27729. EPSS is 0.80%. Act only if a listed version of Astro is a web is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Astro is a web).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.80%
Remediation
Advisory link
Affected products
cpe astro/@astrojs/node

Astro is a web framework. In versions 9.0.0 through 9.5.3, Astro server actions have no default request body size limit, which can lead to memory exhaustion DoS. A single large POST to a valid action endpoint can crash the server process on memory-constrained deployments. On-demand rendered sites built with Astro can define server actions, which automatically parse incoming request bodies (JSON or FormData). The body is buffered entirely into memory with no size limit — a single oversized request is sufficient to exhaust the process heap and crash the server. Astro's Node adapter ( ) creates an HTTP server with no body size protection. In containerized environments, the crashed process is automatically restarted, and repeated requests cause a persistent crash-restart loop. Action names are discoverable from HTML form attributes on any public page, so no authentication is required. The vulnerability allows unauthenticated denial of service against SSR standalone deployments using server actions. A single oversized request crashes the server process, and repeated requests cause a persistent crash-restart loop in containerized environments. Version 9.5.4 contains a fix.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe astro/@astrojs/nodeversion unspecified

How to fix CVE-2026-27729

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-27729. EPSS is 0.80%. Act only if a listed version of Astro is a web is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-770: Allocation of Resources Without Limits or Throttling. EPSS 0.80%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Feb 24, 2026 · NIST NVD

    Detected

    Astro is a web framework. In versions 9.0.0 through 9.5.3, Astro server actions have no default request body size limit, which can lead to memory exhaustion DoS. A single large POST to a valid action endpoint can crash the server process on memory-constrained deployments. On-demand rendered sites built with Astro can define server actions, which automatically parse incoming request bodies (JSON or

  2. Jun 17, 2026 · NIST NVD

    Updated

    Astro is a web framework. In versions 9.0.0 through 9.5.3, Astro server actions have no default request body size limit, which can lead to memory exhaustion DoS. A single large POST to a valid action endpoint can crash the server process on memory-constrained deployments. On-demand rendered sites built with Astro can define server actions, which automatically parse incoming request bodies (JSON or

Sources

  • CVE.orgVulnerability recordCVE-2026-27729

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-27729

    30-day exploitation probability 0.8%

    first.org
  • NIST NVDVulnerability recordCVE-2026-27729

    Astro is a web framework. In versions 9.0.0 through 9.5.3, Astro server actions have no default request body size limit, which can lead to memory exhaustion DoS. A single large POST to a valid action endpoint can crash the server process on memory-constrained deployments. On-dema

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.