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Fencer Vulns
high 8.2

CVE-2026-59731 json

Astro 6.4.7 Authorization Bypass via Decode Iteration Limit and Rewrite Path Canonicalization Mismatch

published 2026-07-08 4 mo ago modified 2026-10-25 15 d ago also EUVD-2026-42341 , GHSA-vj59-8hwv-xxmv

cvss
8.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 26%
public exploits
0
none known

Summary

Astro is a web framework for content-driven websites. Version 6.4.7 performs authorization decisions on a partially decoded pathname after reaching the iterative URL decoder limit, while later rewrite route matching performs an additional decodeURI() operation and can resolve the request to a protected route. This issue is fixed in version 6.4.8.

Patch / fix

  • npm astro 6.4.8
  • astro @astrojs/node 6.4.8

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/withastro/astro/security/advisories/GHSA-vj59-8hwv-xxmv referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
GitHub 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Affected packages

ecosystem package affected fixed in
npm astro
>=6.4.7, <6.4.8
6.4.8

Affected products

  • withastro astro

Classification

Weakness
  • CWE-647 Use of Non-Canonical URL Paths for Authorization Decisions

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.