CVE-2026-48818: Starlette is a lightweight ASGI framework/toolkit

Routine

HIGH 7.5REMOTEUPGRADE

CVE-2026-48818 is a high-severity flaw (CVSS 7.5) affecting starlette. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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, i

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 70%)
CISA exploited list	No
Weakness	CWE-918
Published	2026-06-17
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc. · Vendor: encode

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-17 19:18 UTCPublished CVE record published
2026-10-26 11:10 UTCUpdated Record last modified

encode starlette UPGRADE

Affected: < 1.1.0

Fixed in: 1.1.0

Safe to downgrade to: no unaffected older release

1. Check installed version

pip show starlette

2. UPGRADE to 1.1.0

pip install --upgrade "starlette>=1.1.0"

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-48818?

starlette: upgrade to 1.1.0. Exact commands for each OS are on this page.

Is CVE-2026-48818 being exploited?

CVE-2026-48818 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-48818 affect?

CVE-2026-48818 affects starlette. Severity is high (CVSS 7.5). 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 befor

How urgent is CVE-2026-48818?

Priority 39/100. High severity; Remotely exploitable, no login, no user action

Software pages

Windows vulnerabilities

Related CVEs

CVE-2026-54283 HIGH 7.5 UPGRADE Starlette is a lightweight ASGI framework/toolkit
CVE-2026-48817 MEDIUM 5.3 UPGRADE Starlette is a lightweight ASGI framework/toolkit
CVE-2026-54282 LOW 3.7 UPGRADE Starlette is a lightweight ASGI framework/toolkit
CVE-2026-48710 MEDIUM 6.5 EXPLOITED UPGRADE UPGRADE Kludex Starlette HTTP Request/Response Smuggling Vulnerability

References

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