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Vulnerability details: VCID-yv41-uv7j-buf8
Vulnerability ID VCID-yv41-uv7j-buf8
Aliases CVE-2025-55303
GHSA-xf8x-j4p2-f749
Summary Astro is a web framework for content-driven websites. In versions of astro before 5.13.2 and 4.16.18, the image optimization endpoint in projects deployed with on-demand rendering allows images from unauthorized third-party domains to be served. On-demand rendered sites built with Astro include an /_image endpoint which returns optimized versions of images. A bug in impacted versions of astro allows an attacker to bypass the third-party domain restrictions by using a protocol-relative URL as the image source, e.g. /_image?href=//example.com/image.png. This vulnerability is fixed in 5.13.2 and 4.16.18.
Status Published
Exploitability None
Weighted Severity None
Risk None
Affected and Fixed Packages Package Details
Weaknesses (4)
CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-115 Misinterpretation of Input
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
epss 0.00134 https://api.first.org/data/v1/epss?cve=CVE-2025-55303
cvssv3.1 6.1 https://github.com/withastro/astro
cvssv4 6.4 https://github.com/withastro/astro
generic_textual MODERATE https://github.com/withastro/astro
cvssv3.1 6.1 https://github.com/withastro/astro/commit/4d16de7f95db5d1ec1ce88610d2a95e606e83820
cvssv4 6.4 https://github.com/withastro/astro/commit/4d16de7f95db5d1ec1ce88610d2a95e606e83820
cvssv4 6.9 https://github.com/withastro/astro/commit/4d16de7f95db5d1ec1ce88610d2a95e606e83820
generic_textual MODERATE https://github.com/withastro/astro/commit/4d16de7f95db5d1ec1ce88610d2a95e606e83820
ssvc Track https://github.com/withastro/astro/commit/4d16de7f95db5d1ec1ce88610d2a95e606e83820
cvssv3.1 6.1 https://github.com/withastro/astro/security/advisories/GHSA-xf8x-j4p2-f749
cvssv4 6.4 https://github.com/withastro/astro/security/advisories/GHSA-xf8x-j4p2-f749
cvssv4 6.9 https://github.com/withastro/astro/security/advisories/GHSA-xf8x-j4p2-f749
generic_textual MODERATE https://github.com/withastro/astro/security/advisories/GHSA-xf8x-j4p2-f749
ssvc Track https://github.com/withastro/astro/security/advisories/GHSA-xf8x-j4p2-f749
cvssv3.1 6.1 https://nvd.nist.gov/vuln/detail/CVE-2025-55303
cvssv4 6.4 https://nvd.nist.gov/vuln/detail/CVE-2025-55303
generic_textual MODERATE https://nvd.nist.gov/vuln/detail/CVE-2025-55303
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2025-55303
https://github.com/withastro/astro
https://nvd.nist.gov/vuln/detail/CVE-2025-55303
4d16de7f95db5d1ec1ce88610d2a95e606e83820 https://github.com/withastro/astro/commit/4d16de7f95db5d1ec1ce88610d2a95e606e83820
GHSA-xf8x-j4p2-f749 https://github.com/advisories/GHSA-xf8x-j4p2-f749
GHSA-xf8x-j4p2-f749 https://github.com/withastro/astro/security/advisories/GHSA-xf8x-j4p2-f749
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Found at https://github.com/withastro/astro
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N Found at https://github.com/withastro/astro
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

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none

passive

active

high

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none

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Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Found at https://github.com/withastro/astro/commit/4d16de7f95db5d1ec1ce88610d2a95e606e83820
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

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low

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high

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Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N Found at https://github.com/withastro/astro/commit/4d16de7f95db5d1ec1ce88610d2a95e606e83820
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

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low

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high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N Found at https://github.com/withastro/astro/commit/4d16de7f95db5d1ec1ce88610d2a95e606e83820
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

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passive

active

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Vector: SSVCv2/E:P/A:Y/T:P/P:M/B:A/M:M/D:T/2025-08-19T20:49:42Z/ Found at https://github.com/withastro/astro/commit/4d16de7f95db5d1ec1ce88610d2a95e606e83820
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Found at https://github.com/withastro/astro/security/advisories/GHSA-xf8x-j4p2-f749
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N Found at https://github.com/withastro/astro/security/advisories/GHSA-xf8x-j4p2-f749
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N Found at https://github.com/withastro/astro/security/advisories/GHSA-xf8x-j4p2-f749
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none
Vector: SSVCv2/E:P/A:Y/T:P/P:M/B:A/M:M/D:T/2025-08-19T20:49:42Z/ Found at https://github.com/withastro/astro/security/advisories/GHSA-xf8x-j4p2-f749
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2025-55303
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N Found at https://nvd.nist.gov/vuln/detail/CVE-2025-55303
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

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low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.32555
EPSS Score 0.00134
Published At June 11, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-06-11T17:14:47.808364+00:00 Vulnrichment Import https://github.com/cisagov/vulnrichment/blob/develop/2025/55xxx/CVE-2025-55303.json 38.6.0