VulnerabilityPublished 24 Apr 2026

CVE-2026-41322: withastro astro · Use of Web Browser Cache Containing Sensitive Information

Affects withastro astroSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium : upgrade to 10.0.5 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 10.0.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade withastro astro to 10.0.5.

Affected software

Product	Affected	Fixed in
withastroastro	Affected <10.0.5	Fixed in 10.0.5

AI-suggested

Upgrade to withastro Astro version 10.0.5 or later, where this issue is fixed. Patch status is confirmed by the vendor stating the vulnerability is resolved in 10.0.5. No other mitigation actions are indicated.

Description

@astrojs/node allows Astro to deploy your SSR site to Node targets. Prior to 10.0.5, requesting a static js/css resources from _astro path with an incorrect/malformed if-match header returns a 500 error with a one year cache lifetime instead of 412 in some cases. This has the effect that all subsequent requests to that file, regardless of if-match header will be served a 5xx error instead of the file until the cache expires. This vulnerability is fixed in 10.0.5.

Impact

The impact is limited to availability, causing a denial of service for static JS/CSS resources due to long-lived caching of 5xx error responses. There is no confidentiality or integrity impact reported. The CVSS score of 5.3 reflects a medium severity primarily due to the potential disruption of service.

Summary

The vulnerability in withastro Astro prior to version 10.0.5 involves improper handling of malformed if-match headers when requesting static JS/CSS resources from the _astro path. Instead of returning a 412 Precondition Failed status, the server returns a 500 Internal Server Error with a cache lifetime of one year. This results in clients caching the error response and receiving the 5xx error on subsequent requests until the cache expires, causing a denial of service for those static resources. The issue is resolved in Astro 10.0.5.

CWE-525Use of Web Browser Cache Containing Sensitive Information (opens in a new tab)
Variant weaknessOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The web application does not use an appropriate caching policy that specifies the extent to which each web page and associated form fields should be cached.
Architecture and Design
Protect information stored in cache.
Implementation
Use a restrictive caching policy for forms and web pages that potentially contain sensitive information, such as "no-cache" in the Cache-Control header.
Architecture and Design
Do not store unnecessarily sensitive information in the cache.
OWASP Cheat Sheets
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V8.2.1 (opens in a new tab)
V8.1.1 (opens in a new tab)
V8.1.2 (opens in a new tab)
Attack patterns
Retrieve Embedded Sensitive Data (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/withastro/astro/security/advisories/GHSA-c57f-mm3j-27q9 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 1 May 2026, 20:39 UTC

WeaknessesCWE-525

Technical details

References

Community reviews

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