CVE-2025-48985VulnerabilityPublished 7 Nov 2025Updated 1 Dec 2025

CVE-2025-48985: Vercel AI SDK · Improper Input Validation

Affects Vercel AI SDKSource CVE Database V5

Not known to be exploited · CVSS 3.7 Low · fixed in 5.0.52 : update Vercel AI SDK when convenient.

Data as of 26 Oct 2026, 08:30 UTC

CVSS 3.1 base score

3.7Low

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 20% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 5.0.52

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
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: None: There is no loss of confidentiality within the impacted component.
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 on 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 7 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC 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

Affected software

Product	Affected	Fixed in
Vercel AI SDK	Affected =5.0.51 =5.1.0-beta.8	Fixed in–

AI-suggested

The primary mitigation is to upgrade the Vercel AI SDK to versions 5.0.52, 5.1.0-beta.9, or 6.0.0-beta where the vulnerability is fixed. Organizations should audit their software dependencies to identify usage of affected SDK versions and enforce timely patching. Additionally, implement strict server-side validation of uploaded files beyond client-side checks, including MIME type verification, file signature validation, and content scanning for malware. Employ application-layer firewalls or web application firewalls (WAFs) to detect and block suspicious file uploads. Restrict file upload permissions and storage locations to minimize potential damage from unauthorized files. Conduct regular security assessments and penetration testing focused on file upload functionalities. Finally, monitor logs and alerts for unusual upload activities and establish incident response procedures to quickly address any exploitation attempts.

Description

A vulnerability in Vercel’s AI SDK has been fixed in versions 5.0.52, 5.1.0-beta.9, and 6.0.0-beta. This issue may have allowed users to bypass filetype whitelists when uploading files. All users are encouraged to upgrade. More details: https://vercel.com/changelog/cve-2025-48985-input-validation-bypass-on-ai-sdk

Impact

For European organizations, the impact of CVE-2025-48985 is primarily related to the integrity of applications using the vulnerable Vercel AI SDK versions. Attackers could bypass filetype restrictions and upload unauthorized files, potentially leading to injection of malicious content or unauthorized modifications. While the vulnerability does not directly compromise confidentiality or availability, the integrity breach could facilitate secondary attacks such as webshell deployment, malware hosting, or defacement. Organizations relying on Vercel’s AI SDK for critical or customer-facing applications may face reputational damage and operational disruptions if exploited. Given the low CVSS score and high attack complexity, widespread exploitation is unlikely, but targeted attacks against high-value assets remain a concern. European entities with stringent compliance requirements around data integrity and software supply chain security should prioritize remediation to avoid regulatory penalties and maintain trust.

Summary

CVE-2025-48985 is a security vulnerability identified in the Vercel AI SDK, a software development kit used to integrate AI functionalities into applications hosted on Vercel's platform. The vulnerability specifically involves an input validation bypass that allows attackers to circumvent filetype whitelisting mechanisms during file uploads. This means that malicious actors could upload files with disallowed or potentially harmful extensions by exploiting the flaw in the SDK's validation logic. The affected versions include 5.0.51 and 5.1.0-beta.8, with patches released in versions 5.0.52, 5.1.0-beta.9, and 6.0.0-beta. The vulnerability is categorized under CWE-20 (Improper Input Validation), indicating that the SDK did not sufficiently verify or restrict input data before processing it. According to the CVSS v3.1 scoring, the vulnerability has a score of 3.7 (low severity), with an attack vector of network (AV:N), high attack complexity (AC:H), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no confidentiality impact (C:N), low integrity impact (I:L), and no availability impact (A:N). This suggests that while exploitation is possible remotely without authentication or user interaction, the complexity of the attack is high, and the impact is limited to integrity, such as unauthorized file uploads that could potentially modify or inject malicious content. No known exploits have been reported in the wild, indicating that the threat is currently theoretical but should be addressed proactively. The vulnerability primarily affects applications that rely on the Vercel AI SDK for file upload functionalities, potentially exposing them to risks such as uploading malicious scripts or unauthorized files that could be used for further attacks or data manipulation.

CWE-20Improper Input Validation (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #18OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Attack Surface Reduction
Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of…
Architecture and Design · Libraries or Frameworks
Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Buffer Overflow via Environment Variables (opens in a new tab)
Server Side Include (SSI) Injection (opens in a new tab)
Cross Zone Scripting (opens in a new tab)
Command Line Execution through SQL Injection (opens in a new tab)
Object Relational Mapping Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 1 Dec 2025, 21:19 UTC

WeaknessesCWE-20

Technical details

References

Community reviews

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