VulnerabilityPublished 2 Jul 2026

@asymmetric-effort/specifyjs: No redirect target validation

Affects @asymmetric-effort/specifyjsSource GCVE Database

CVSS 6.9 Medium : upgrade to 0.2.136 when convenient.

Data as of 3 Jul 2026, 22:49 UTC

CVSS 4.0 base score

6.9Medium

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

Patch: Available – fixed in 0.2.136

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

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: Low
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

What to do

Upgrade @asymmetric-effort/specifyjs to 0.2.136.

Affected software

Product	Affected	Fixed in
npm@asymmetric-effort/specifyjs	Affected <0.2.136	Fixed in 0.2.136

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AI-suggested

This vulnerability is fixed in @asymmetric-effort/specifyjs version 0.2.136 and later. Users should upgrade to v0.2.136 or above to ensure secureFetch rejects redirects by default. If redirects are necessary, callers must explicitly specify { redirect: 'follow' } and ensure they trust the redirect targets. No additional mitigation is required beyond upgrading or carefully managing redirect options.

Description

## Finding **Location**: `core/src/shared/secure-fetch.ts` `assertSecureUrl` validated only the initial request URL. The `fetch()` API follows redirects by default (up to 20 hops). A request to a valid `https://` URL could redirect to `http://internal-service/` or other unvalidated destinations. ## Status **Fixed in v0.2.136** — `secureFetch` now defaults to `redirect: 'error'` which rejects any redirect. Callers can override with `{ redirect: 'follow' }` if they trust the target.

Impact

An attacker could exploit this vulnerability by causing a request to a trusted HTTPS endpoint to be redirected to an untrusted or internal HTTP endpoint without validation. This could lead to unintended data exposure or interaction with internal services that were not meant to be accessed externally. The vulnerability is rated as medium severity and does not require privileges or user interaction to exploit.

Summary

The vulnerability in @asymmetric-effort/specifyjs (prior to v0.2.136) involves the secureFetch function's lack of validation for redirect targets. While the initial request URL was validated by assertSecureUrl, the fetch API's default behavior to follow redirects (up to 20 hops) was not restricted. This allowed a request to a validated HTTPS URL to be redirected to an unvalidated and potentially insecure HTTP URL, such as an internal service. The fix implemented in v0.2.136 sets secureFetch to default to redirect: 'error', which rejects redirects unless the caller explicitly opts in to follow them.

CWE-918Server-Side Request Forgery (opens in a new tab)
Base weaknessCWE Top 25 (2025): #22OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
Implementation · Operation
If there is a known list of applications, IP, hostname, and/or domains to which the product is allowed to communicate, then use allowlists to ensure that outgoing requests are restricted to these known entities. The allowlists could be in the application code or possibly enforced by firewalls or network segmentation.
Implementation · Operation
If the product is expected to be able to connect to arbitrary IP addresses or domains, consider using a denylist that includes private network addresses, internal domain names, etc. The denylist could be in the application code or possibly enforced by firewalls or network segmentation.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
OWASP Cheat Sheets
Server Side Request Forgery Prevention (opens in a new tab)
Unvalidated Redirects and Forwards (opens in a new tab)
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.6.1 (opens in a new tab)
V5.2.6 (opens in a new tab)
Attack patterns
Server Side Request Forgery (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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What to do

Affected software

Description

AI analysisMachine-generated, updated 2 Jul 2026, 23:14 UTC

WeaknessesCWE-918

Technical details

References

Community reviews

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