VulnerabilityPublished 13 Nov 2026

CVE-2026-128119: sveltejs kit · Incorrect Authorization

Affects sveltejs kitSource CVE Database V5

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Not known to be exploited · CVSS 5.9 Medium : upgrade to 3.1.1 when convenient.

Data as of 13 Nov 2026, 19:51 UTC

CVSS 3.1 base score

5.9Medium

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.1	5.9

Patch: Available – fixed in 3.1.1

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

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

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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
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: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 Nov 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 13 Nov 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 sveltejs kit to 3.1.1.

Affected software

Product	Affected	Fixed in
sveltejskit	Affected >=2.60.1 <3.1.1	Fixed in 3.1.1

AI-suggested

Upgrade SvelteKit to version 3.1.1 or later, where this issue is fixed. No other mitigation or temporary workaround is indicated.

Description

CVE-2026-128119 is an authorization flaw in SvelteKit versions from 2.60.1 up to but not including 3.1.1. The issue occurs when using the experimental remote functions flag, allowing separate non-exported query.batch functions to share the same generated identifier. This can cause arguments intended for one function to be passed to another, potentially disclosing sensitive function arguments. The vulnerability is fixed in version 3.1.1.

Impact

The vulnerability can lead to unauthorized disclosure of function arguments between separate private functions within a batched request context. This impacts confidentiality but does not affect integrity or availability. The CVSS score of 5.9 (medium severity) reflects a network attack vector with high complexity and no privileges required, resulting in high confidentiality impact but no integrity or availability impact.

Summary

SvelteKit, a web application framework, had an incorrect authorization vulnerability (CWE-863) in versions >=2.60.1 and <3.1.1 when using the experimental remote functions flag. This flaw allowed multiple private query.batch functions to be assigned the same identifier, leading to cross-function argument leakage during shared request batching. This could result in unintended disclosure of function arguments between isolated functions. The issue was resolved in version 3.1.1.

CWE-863Incorrect Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #17OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 13 Nov 2026, 19:51 UTC

WeaknessesCWE-863

Technical details

References

Community reviews

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