CVE-2026-25479 | Litestar has an AllowedHosts validation bypass due to unescaped regex metacharacters in configured host patterns

Exp

Litestar is an Asynchronous Server Gateway Interface (ASGI) framework. Prior to 2.20.0, in litestar.middleware.allowed_hosts, allowlist entries are compiled into regex patterns in a way that allows regex metacharacters to retain special meaning (e.g., . matches any character). This enables a bypass where an attacker supplies a host that matches the regex but is not the intended literal hostname. This vulnerability is fixed in 2.20.0.

Published: 2026-02-09 Last update: 2026-02-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-25479 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.03%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-25479

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-25479

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-10 — 0.03% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-25479

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 2.5 [email protected]

Weakness enumeration for CVE-2026-25479

GitHub Security Advisory for CVE-2026-25479

GHSA-93ph-p7v4-hwh4 · Severity: medium · Ecosystem: pip — Litestar's AllowedHosts has a validation bypass due to unescaped regex metacharacters in configured host patterns

Affected software / configurations for CVE-2026-25479

Vendor Product Version Raw CPE
litestar litestar < 2.20.0 cpe:2.3:a:litestar:litestar:*:*:*:*:*:*:*:*

References for CVE-2026-25479

cvelogic Threat Intelligence