VulnerabilityPublished 6 Oct 2025

CVE-2025-59152: litestar · Reliance on Untrusted Inputs in a Security Decision

Affects litestarSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 15:59 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
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: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Oct 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 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

Affected software

Product	Affected	Fixed in
litestar-org litestar	Affected =2.17.0	Fixed in–

AI-suggested

European organizations should immediately upgrade Litestar to version 2.18.0 or later, which contains the patch for this vulnerability. Until the upgrade is applied, organizations should implement additional controls to validate or sanitize the X-Forwarded-For header before it is used for rate limiting. This can include configuring middleware to trust only headers from known and secure proxies or load balancers, ignoring client-supplied X-Forwarded-For headers from untrusted sources, or using alternative client identification methods such as authenticated tokens or cookies. Network-level protections like Web Application Firewalls (WAFs) can be configured to detect and block suspicious header manipulation or IP rotation patterns. Monitoring and alerting on unusual request rates or header anomalies can help detect exploitation attempts early. Additionally, consider implementing rate limiting based on multiple factors (e.g., user accounts, API keys) rather than solely on IP addresses. Conduct thorough testing after applying patches or configuration changes to ensure rate limiting functions as intended without introducing regressions.

Description

Litestar is an Asynchronous Server Gateway Interface (ASGI) framework. In version 2.17.0, rate limits can be completely bypassed by manipulating the X-Forwarded-For header. This renders IP-based rate limiting ineffective against determined attackers. Litestar's RateLimitMiddleware uses `cache_key_from_request()` to generate cache keys for rate limiting. When an X-Forwarded-For header is present, the middleware trusts it unconditionally and uses its value as part of the client identifier. Since clients can set arbitrary X-Forwarded-For values, each different spoofed IP creates a separate rate limit bucket. An attacker can rotate through different header values to avoid hitting any single bucket's limit. This affects any Litestar application using RateLimitMiddleware with default settings, which likely includes most applications that implement rate limiting. Version 2.18.0 contains a patch for the vulnerability.

Impact

For European organizations, this vulnerability poses a significant risk to service availability, especially for those relying on Litestar 2.17.0 with default RateLimitMiddleware settings. Attackers can bypass rate limits and launch denial-of-service attacks, potentially causing service outages or degraded performance. This can affect customer-facing applications, internal APIs, and critical infrastructure relying on Litestar. The inability to enforce effective rate limiting may also increase the risk of automated abuse, credential stuffing, or brute-force attacks. While confidentiality and integrity remain intact, the availability impact can disrupt business operations, damage reputation, and incur financial losses. Organizations in sectors with high availability requirements, such as finance, healthcare, and e-commerce, are particularly vulnerable. Additionally, the flaw could be exploited as part of multi-vector attacks, compounding risks. The lack of authentication or user interaction for exploitation means attackers can operate remotely and anonymously, increasing the threat surface.

Summary

The vulnerability CVE-2025-59152 affects Litestar version 2.17.0, an ASGI framework widely used for asynchronous Python web applications. The issue lies in the RateLimitMiddleware component, which implements IP-based rate limiting by generating cache keys from client IP addresses. When the X-Forwarded-For HTTP header is present, the middleware trusts this header without validation and uses its value as the client identifier for rate limiting. Since the X-Forwarded-For header can be arbitrarily set by clients, attackers can spoof different IP addresses in this header to create multiple distinct rate limit buckets. This allows attackers to bypass rate limits by rotating through spoofed IP addresses, effectively nullifying the rate limiting protection. The vulnerability is classified under CWE-807 (Reliance on Untrusted Inputs in a Security Decision). The CVSS v3.1 score is 7.5 (high), reflecting the ease of exploitation (no authentication or user interaction required), network attack vector, and the significant impact on availability. The flaw does not compromise confidentiality or integrity but enables denial-of-service conditions by allowing attackers to flood services without restriction. The issue was reserved on 2025-09-09 and published on 2025-10-06. Litestar version 2.18.0 includes a patch that corrects this behavior by presumably validating or ignoring untrusted X-Forwarded-For headers for rate limiting purposes. No known exploits are reported in the wild yet.

CWE-807Reliance on Untrusted Inputs in a Security Decision (opens in a new tab)
Base weaknessLikelihood of exploit: HighOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product uses a protection mechanism that relies on the existence or values of an input, but the input can be modified by an untrusted actor in a way that bypasses the protection mechanism.
Architecture and Design · Attack Surface Reduction
Store state information and sensitive data on the server side only.
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.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
OWASP Cheat Sheets
Secure Design Principles (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 6 Oct 2025, 15:37 UTC

WeaknessesCWE-807

Technical details

References

Community reviews

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