CVE Intelligence
High SSRF exploit reference

CVE-2026-25545 — Astro has Full-Read SSRF in error rendering via Host: header injection

Astro is a web framework. Prior to version 9.5.4, Server-Side Rendered pages that return an error with a prerendered custom error page (eg. `404.astro` or `500.astro`) are vulnerable to SSRF. If the `Host:` header is changed to an attacker's server, it will be fetched on `/500.html` and they can redirect this to any internal URL to read the response body through the first request. An attacker who can access the application without `Host:` header validation (eg. through finding the origin IP behind a proxy, or just by default) can fetch their own server to redirect to any internal IP. With this they can fetch cloud metadata IPs and interact with services in the internal network or localhost. For this to be vulnerable, a common feature needs to be used, with direct access to the server (no proxies). Version 9.5.4 fixes the issue.

Published Feb 23, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

Detection templates (Nuclei) · 1
How the score was calculated
  • Public exploit/PoC (nuclei)+4
  • EPSS 2% (30-day exploitation probability)+12
  • Technical severity (high)+6
  • CISA SSVC: exploitation "poc"+5

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
1.98%
ahead of 80% of scored CVEs · Oct 14, 2026
Affects
Astro
@astrojs/node and 1 more
CVSS base
8.6
High · 3 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Proof of concept
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Documented patch — github.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Astro @astrojs/node, Withastro Astro).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. Apply the fixed version or the patch documented under Remediation.
  4. Search available logs for exploit probes matching the vulnerability class (ssrf), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Astro @astrojs/node < 9.5.4 Vulnerable NIST National Vulnerability Database
Withastro Astro version < 9.5.4 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
6.9 CVSS 4.0 Medium — — security-advisories@github.com via NIST National Vulnerability Database
6.9 CVSS 4.0 Medium — — GitHub_M via CVE Program (cve.org) e CISA ADP
8.6 CVSS 3.1 High 3.9 4.0 nvd@nist.gov via NIST National Vulnerability Database
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-918 · Server-Side Request Forgery (SSRF)

Other CVEs with this weakness →

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Detection templates (Nuclei)

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 1.98%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Monitor outbound requests from the server to internal IPs and cloud metadata endpoints.
web/proxy/WAF logsnetwork IDS/IPSegress traffic

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · withastro/astro
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Fix documented
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 8.6
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVE published
    Feb 23, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

3 on the record

Elsewhere on this site

Astro
every CVE for this vendor
SSRF
same class
CWE-918
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-59731 Astro 6.4.7 Authorization Bypass via Decode Iteration Limit and Rewrite Path Canonicalization Mismatch Jul 8, 2026
  • CVE-2026-54299 Astro: Host-header full-read SSRF in core prerendered error-page fetch (prerenderedErrorPageFetch default + unvalidated createRequestFromNodeRequest URL) Jun 22, 2026
  • CVE-2026-54298 Astro: XSS via Unescaped Attribute Names in Spread Props Jun 22, 2026
  • CVE-2026-54300 @astrojs/netlify broadens Astro image.remotePatterns in Netlify Image CDN config Jun 22, 2026
  • CVE-2026-50146 Astro: Reflected XSS via unescaped slot name Jun 22, 2026
  • CVE-2026-45028 Astro: Server island encrypted parameters vulnerable to cross-component replay May 13, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-25545 is "Astro has Full-Read SSRF in error rendering via Host: header injection", rated High. It affects @astrojs/node (Astro); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.6 describes technical severity. EPSS 1.98% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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