← Vulnerability feed

Vulnerability record · CVE-2026-48818 · published 17 June 2026

CVE-2026-48818: Encode starlette server-side request forgery (ssrf) vulnerability

Encode · Starlette

Starlette is a lightweight ASGI framework/toolkit. In versions 1.0.1 and earlier, StaticFiles on Windows is vulnerable to SSRF. An UNC path such as \\attacker.com\share can cause os.path.realpath to initiate an outbound SMB connection before the path is rejected, exposing the service account’s NTLMv2 credentials for offline cracking or relay even though the HTTP response is only a 404. The issue affects default follow_symlink=False deployments, including frameworks built on Starlette such as FastAPI; POSIX systems and follow_symlink=True are unaffected. The issue is fixed in 1.1.0.

7.5 CVSS 3.1 High EPSS 0.65% · top 51.0% CWE-918 · Server-side request forgery (SSRF)
7.5CVSS 3.1 base score
0.65%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
11References
4 Aug 2026Last modified by NVD

Description

Starlette is a lightweight ASGI framework/toolkit. In versions 1.0.1 and earlier, StaticFiles on Windows is vulnerable to SSRF. An UNC path such as \\attacker.com\share can cause os.path.realpath to initiate an outbound SMB connection before the path is rejected, exposing the service account’s NTLMv2 credentials for offline cracking or relay even though the HTTP response is only a 404. The issue affects default follow_symlink=False deployments, including frameworks built on Starlette such as FastAPI; POSIX systems and follow_symlink=True are unaffected. The issue is fixed in 1.1.0.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/Kludex/starlette/commit/fd53168a7767b6b55ba5af787fd88f49e33cabc5 Patch
https://github.com/Kludex/starlette/pull/3287 Patch
https://github.com/Kludex/starlette/releases/tag/1.1.0 Release Notes
https://github.com/Kludex/starlette/security/advisories/GHSA-wqp7-x3pw-xc5r MitigationVendor Advisory
https://github.com/pypa/advisory-database/tree/main/vulns/starlette/PYSEC-2026-2281.yaml
https://access.redhat.com/errata/RHSA-2026:30087
https://access.redhat.com/errata/RHSA-2026:30088
https://access.redhat.com/errata/RHSA-2026:30089
https://access.redhat.com/security/cve/CVE-2026-48818
https://bugzilla.redhat.com/show_bug.cgi?id=2490020
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48818.json

Track CVE-2026-48818 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

6.5CVE-2026-48710Starlette Host header validation flaw enables request.url path mismatchStarlette before 1.0.1 did not validate the HTTP Host header before using it to rebuild request.url, so a malformed Host value could make request.url…KEVEPSS 7.1%analysed7.5CVE-2026-54283Encode starlette allocation without limits vulnerabilityStarlette is a lightweight ASGI framework/toolkit. From 0.4.1 until 1.3.1, request.form() accepts max_fields and max_part_size to bound resource cons…EPSS 0.48%7.5CVE-2023-29159Encode starlette path traversal vulnerabilityDirectory traversal vulnerability in Starlette versions 0.13.5 and later and prior to 0.27.0 allows a remote unauthenticated attacker to view files i…EPSS 2.0%7.5CVE-2023-30798Encode starlette uncontrolled resource consumption vulnerabilityThere MultipartParser usage in Encode's Starlette python framework before versions 0.25.0 allows an unauthenticated and remote attacker to specify an…EPSS 1.3%5.3CVE-2026-54282Encode starlette vulnerabilityStarlette is a lightweight ASGI framework/toolkit. Prior to 1.3.0, the HTTP request path is not validated before being used to reconstruct request.ur…EPSS 0.27%5.3CVE-2026-48817Encode starlette vulnerabilityStarlette is a lightweight ASGI framework/toolkit. In versions 1.0.1 and below, when dispatching a request, HTTPEndpoint selects the handler by lower…EPSS 0.35%10.0CVE-2026-83548SonicWall SMA1000 pre-auth SSRF via alternate access pathThe SMA1000 Appliance Work Place interface exposes an unintended alternate access path that allows server-side request forgery before authentication.…KEVEPSS 8.8%analysed10.0CVE-2026-49869Kestra OSS auth bypass via path suffix match enables RCEKestra OSS AuthenticationFilter whitelists the public config endpoint using request.getPath().endsWith("/configs"), a suffix match instead of an exac…KEVEPSS 2.1%analysed

Source: NIST National Vulnerability Database (record CVE-2026-48818), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.