What is the CVSS score of CVE-2026-108770?

CVE-2026-108770 has a CVSS 4.0 base score of 6.9 (Medium). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. EPSS exploitation probability: 0.4%.

Is there a patch available for CVE-2026-108770?

Yes, a patch is available for CVE-2026-108770. Update the affected software to the latest version immediately.

Appwrite CVE-2026-108770

EUVD-2026-97127 MEDIUM

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

2026-10-11 VulDB

GHSA-cfw6-h8vp-h745

PHP SSRF N A Appwrite

6.9

CVSS 4.0 · Vendor: VulDB

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Identify exposed screenshot endpoint
Delivery

Submit internal/rebinding url parameter
Exploit

Bypass host validation via DNS rebinding
Execution

Browser renders internal resource
Impact

Exfiltrate internal data via screenshot

Vulnerability Assessment

Weakness	CWE CWE-918 OWASP Top 10:2025 A01:2025 - Broken Access Control ASVS 5.0 V4 - API and Web Service URL allowlisting, SSRF prevention MITRE ATT&CK 2 techniques across 2 tactics: Initial Access, Credential Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Exploitation Conditions	Requires the Appwrite Browser Screenshot Service (the Avatars screenshot endpoint backed by the headless 'browser' container) to be deployed and reachable, running version ≤2.3.0 before the 2.4.0 fix. The attacker supplies a malicious 'url' parameter; because the headless browser resolves the hostname itself, pre-patch validation can be bypassed via DNS rebinding to reach internal services or cloud metadata endpoints. The CVSS vector states PR:N (unauthenticated), but operators should confirm whether their deployment gates this endpoint behind an API key or project session, which would meaningfully limit exploitation. Impact is bounded to confidentiality-style disclosure via the rendered screenshot; no integrity or availability effect is indicated.
Impact	This is a genuine but moderate-priority issue. The provided CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N) indicates a network-reachable, low-complexity, unauthenticated vulnerability, which raises exposure, but the impact is deliberately narrow: only VC:L (low confidentiality) with no integrity (VI:N) or availability (VA:N) and no subsequent-system impact (SC/SI/SA:N), yielding a score of 6.9 (Medium). No EPSS score, no CISA KEV listing, and no vendor-confirmed exploit code are present in the data, so exploitation is 'no public exploit identified at time of analysis' - note that a linked third-party GitHub issue (godzeo/vulhub/issues/2) exists but does not itself confirm weaponized POC. The signals are internally consistent rather than conflicting: an SSRF that is remotely triggerable but limited to low-confidence information disclosure. The main caveat is the authentication context - the vector asserts PR:N (unauthenticated), yet Appwrite avatar/screenshot endpoints typically operate within a project/API context, so defenders should verify whether an API key or session is required in their deployment; if so, real-world risk is lower than PR:N implies. The source-code evidence (DNS-rebinding mitigation and cloud-metadata header handling added in the fix) suggests the practical upside for an attacker - reaching internal services or cloud metadata - may exceed the modest VC:L rating, warranting prompt patching despite the Medium score.
Exploit ScenarioDerived	A remote attacker calls the Browser Screenshot Service endpoint with a crafted 'url' parameter pointing at an internal address (or a public domain that DNS-rebinds to one such as 169.254.169.254 or an internal service name), causing the server-side headless browser to fetch and render that internal resource. The returned screenshot can leak internal web interfaces or cloud metadata content back to the attacker. No public exploit is identified at time of analysis, though the attack is low-complexity and network-triggerable per the CVSS vector.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).

Patch available 0.4% exploitation probability (EPSS)

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AnalysisAIv1 – Oct 11, 2026

Server-side request forgery in Appwrite 2.3.0 and earlier allows remote attackers to make the Browser Screenshot Service (exposed through the Avatars screenshot endpoint and its 'url' parameter) fetch arbitrary attacker-chosen URLs, reaching internal services or cloud metadata endpoints; because the headless browser resolves the hostname itself, the pre-patch hostname validation can be bypassed via DNS rebinding. Per the CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N), exploitation is unauthenticated over the network with confidentiality-only impact (score 6.9), and the independent assessment rates this a genuine but moderate-priority issue bounded to information disclosure through the rendered screenshot. No public exploit was identified at time of analysis, and exploitation requires the screenshot endpoint to be deployed and reachable; the vendor-released fix is Appwrite 2.4.0 (patch commit 393255e7302ae5503331d45802e2eee01c6a47fe, PR 13995).

RemediationAI

Upgrade to Appwrite 2.4.0 (vendor-released patch; commit 393255e7302ae5503331d45802e2eee01c6a47fe, PR https://github.com/appwrite/appwrite/pull/13995, release https://github.com/appwrite/appwrite/releases/tag/2.4.0), which validates the 'url' parameter with the new PublicURL validator and moves the headless browser container onto an isolated 'browser' network with public DNS resolvers only. If immediate upgrade is not possible, apply the deployment portion of the patch as a compensating control: detach the browser container from the appwrite network and attach it to a dedicated network whose DNS is restricted to public resolvers (1.1.1.1/8.8.8.8), so internal hostnames such as redis or appwrite-mariadb cannot be resolved - the trade-off is that any legitimate reliance on internal name resolution from the browser container will break. Additionally, block egress from the browser container to link-local and private ranges, especially 169.254.169.254, and enable IMDSv2-style protections on cloud instances; restricting browser egress to an allowlist of expected external hosts is more effective but will cause legitimate screenshot requests for unlisted sites to fail. If the Avatars screenshot feature is not needed, disable it entirely, and where possible require an API key or valid project session on the avatars endpoints - noting that the assessed CVSS vector is PR:N (unauthenticated), so operators should confirm whether their own deployment actually gates these routes, since that gate meaningfully limits exposure. Because exploitation depends on attacker-influenced DNS, running the browser container with a resolver that does not honor attacker-controlled rebinding (or pinning resolution for the validated host) reduces risk, though the primary fix remains upgrading to 2.4.0.

Affected VersionsENISA

Appwrite 2.1

Appwrite 2.3.0

Appwrite 2.2

Appwrite 2.0

Affected Packages

euvd appwrite no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This is a classic CWE-918 server-side request forgery rooted in a validation/resolution mismatch (a time-of-check-to-time-of-use gap). Appwrite's Avatars screenshot endpoint (src/Appwrite/Platform/Modules/Avatars/Http/Screenshots/Get.php) accepted a user-supplied 'url' parameter and passed it through the PHP-level PublicHostname validator, which checked that the hostname resolved to a publicly routable address. The actual fetch, however, is performed by a separate headless Chromium 'browser' container that performs its own DNS resolution, so an attacker controlling DNS (rebinding) could return a public IP during validation and an internal IP (e.g. redis, appwrite-mariadb, or the 169.254.169.254 cloud metadata service) at fetch time, or simply point the browser at internal service names. The fix introduces a new Appwrite\Network\Validator\PublicURL class (extends Utopia\Validator\URL, additionally requiring a known public domain or public IP literal validated via Utopia\Domains\Domain::isKnown() and PublicHostname) and applies it consistently across the Screenshots, Image, and Favicon avatar endpoints. Critically, the patch also changes docker-compose.yml to place the browser container on a dedicated 'browser' network, removes its attachment to the appwrite network, and pins its DNS to public resolvers (1.1.1.1, 8.8.8.8) so it cannot resolve internal service names - an architectural egress restriction that complements the input validation. The stack is PHP/Utopia-based, consistent with the PHP and SSRF tags.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (VulDB) PRIMARY 6.9 MEDIUM

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

vuln.today AI 5.3 MEDIUM

Remotely and unauthenticated-triggerable low-complexity SSRF (AV:N/AC:L/PR:N/UI:N) yielding limited internal-resource disclosure (C:L) with no integrity or availability impact.

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

4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (VulDB).

CVSS VectorVendor: VulDB

Attack Vector

Network

Attack Complexity

Low

Attack Requirements

None

Privileges Required

None

User Interaction

None

Vulnerable system: Confidentiality

Low

Vulnerable system: Integrity

None

Vulnerable system: Availability

None

Subsequent system: Confidentiality

None

Subsequent system: Integrity

None

Subsequent system: Availability

None

DescriptionCVE.org

A weakness has been identified in Appwrite up to 2.3.0. This vulnerability affects the function PublicHostname of the file src/Appwrite/Platform/Modules/Avatars/Http/Screenshots/Get.php of the component Browser Screenshot Service. This manipulation of the argument url causes server-side request forgery. The attack can be initiated remotely. Upgrading to version 2.4.0 is able to resolve this issue. Patch name: 393255e7302ae5503331d45802e2eee01c6a47fe. You should upgrade the affected component.

Threat Intelligence Overview

EPSS Score

0.4%

Top 67% exploitable

Prevalence

Medium

popular open-source self-hosted backend platform, common among developers

Social Media

Sightings

Data Quality

7 sources

Confidence: High

EUVD

NVD

CVE.org

EPSS CIRCL

GitHub

VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity MEDIUM

CISA KEV No

Public POC No

EPSS 0.4%

Patch available Yes

Active threat No

Deciding rule

MEDIUM severity (CVSS 4.0-6.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.