How severe is CVE-2026-48710?

CVE-2026-48710 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-48710?

CVE-2026-48710 affects the following packages: starlette (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-48710?

Update starlette to 1.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48710 is resolved across your whole dependency graph.

How do I detect CVE-2026-48710 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for starlette. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-48710 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-48710?

O3 pinpoints whether CVE-2026-48710 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-48710 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2026-48710, including . All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2026-48710?

CVE-2026-48710 has an EPSS (Exploit Prediction Scoring System) score of 1.4%, placing it in the 70th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-48710?

CVE-2026-48710 is classified as CWE-444 (CWE-444), CWE-1289 (CWE-1289). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Is there exploit tooling available for CVE-2026-48710?

A Nuclei detection template exists for CVE-2026-48710, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2026-48710 published, and has it been updated?

CVE-2026-48710 was published on May 26, 2026 and was last updated on July 18, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

CVE-2026-48710

MEDIUM

Starlette has missing Host header validation that poisons request.url.path, bypassing path-based security checks

Also known asGHSA-86qp-5c8j-p5mrPYSEC-2026-161X41-2026-002

Published

May 26, 2026

Updated

Jul 18, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

EPSS Exploitation Probability

via FIRST.org ↗

1.4%probability of exploitation in next 30 days

Lower Risk70th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐍starlette

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Starlette is a lightweight ASGI framework/toolkit. Prior to version 1.0.1, the HTTP Host request header was not validated before being used to reconstruct request.url. Because the routing algorithm relies on the raw HTTP path while request.url is rebuilt from the Host header, a malformed header could make request.url.path differ from the path that was actually requested. Middleware and endpoints that apply security restrictions based on request.url (rather than the raw scope path) could therefore be bypassed. Users should upgrade to a version greater than or equal to version 1.0.1, which validates the Host header against the grammar of RFC 9112 §3.2 / RFC 3986 §3.2.2 when constructing request.url and falls back to scope["server"] for malformed values.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`starlette`	all versions	1.0.1

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

eris-ths/supply-chain-guard

Detect, assess, and respond to supply chain attacks across npm/yarn and

⭐ 3🍴 0Jul 2026

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for starlette. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update starlette to 1.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48710 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-48710 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-48710. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Starlette is a lightweight ASGI framework/toolkit. Prior to version 1.0.1, the HTTP `Host` request header was not validated before being used to reconstruct `request.url`. Because the routing algorithm relies on the raw HTTP path while `request.url` is rebuilt from the `Host` header, a malformed header could make `request.url.path` differ from the path that was actually requested. Middleware and endpoints that apply security restrictions based on `request.url` (rather than the raw `scope` path) could therefore be bypassed. Users should upgrade to a version greater than or equal to version 1.0.

O3 Security · Impact-Aware SCA

Is CVE-2026-48710 in your dependencies?

O3 detects CVE-2026-48710 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works