CVE catalog

CVE-2025-62727

starlette: CVE-2025-62727

Severity: High · CVSS 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: Oct 28, 2025, 8:14:53 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.80% · Oct 25, 2026

Starlette is a lightweight ASGI framework/toolkit. Starting in version 0.39.0 and prior to version 0.49.1 , an unauthenticated attacker can send a crafted HTTP Range header that triggers quadratic-time processing in Starlette's FileResponse Range parsing/merging logic. This enables CPU exhaustion per request, causing denial‑of‑service for endpoints serving files (e.g., StaticFiles or any use of FileResponse). This vulnerability is fixed in 0.49.1.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	starlette	sid	`1.9.0-1`	fixed
Debian	starlette	forky	`1.9.0-1`	fixed
Debian	starlette	trixie	`0.46.1-3+deb13u3`	fixed
Debian	starlette	trixie-security	`0.46.1-3+deb13u3`	fixed
Debian	starlette	bookworm	`0.26.1-1+deb12u1`	not affected
Debian	starlette	bookworm-security	`0.26.1-1+deb12u2`	not affected
Opensuse	python-sse-starlette	tumbleweed	`3.2.0-1.1`	fixed
Opensuse	python-starlette	tumbleweed	`0.49.1-1.1`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	starlette	source	sid	`0.50.0-1`	not yet assigned	Not reported	[1119662]
Debian	starlette	source	forky	`0.50.0-1`	not yet assigned	Not reported	[1119662]
Debian	starlette	source	trixie	`0.46.1-3+deb13u1`	not yet assigned	Not reported	[1119662]
Debian	starlette	source	bookworm	`Not affected`	unimportant	Not reported	[1119662]
Opensuse	python-sse-starlette	rpm	tumbleweed	`3.2.0-1.1`	Not reported	OPENSUSE-SU-2026:10109-1	Not reported
Opensuse	python-starlette	rpm	tumbleweed	`0.49.1-1.1`	Not reported	OPENSUSE-SU-2025:15696-1	Not reported

[Debian bug #1119662]

OpenFactory catalog packages

[openSUSE Tumbleweed]

[python313-sse-starlette]Unknown
Source package: [python-sse-starlette]
Details (1)
- 3.4.8-1.1 · noarch · tumbleweed
  Unknown · Fixed: 3.2.0-1.1
  Version impact unknown
  dsa · python-sse-starlette · opensuse · tumbleweed
[python313-starlette]Unknown
Source package: [python-starlette]
Details (1)
- 1.6.0-1.1 · noarch · tumbleweed
  Unknown · Fixed: 0.49.1-1.1
  Version impact unknown
  dsa · python-starlette · opensuse · tumbleweed
[python314-sse-starlette]Unknown
Source package: [python-sse-starlette]
Details (1)
- 3.4.8-1.1 · noarch · tumbleweed
  Unknown · Fixed: 3.2.0-1.1
  Version impact unknown
  dsa · python-sse-starlette · opensuse · tumbleweed
[python314-starlette]Unknown
Source package: [python-starlette]
Details (1)
- 1.6.0-1.1 · noarch · tumbleweed
  Unknown · Fixed: 0.49.1-1.1
  Version impact unknown
  dsa · python-starlette · opensuse · tumbleweed

[Debian 12 (Bookworm)]

[python3-starlette]Not affected
Source package: [starlette]
Details (4)
- 0.26.1-1+deb12u1 · all · bookworm
  Not affected
  dsa · starlette · debian · bookworm
- 0.26.1-1+deb12u1 · all · bookworm
  Not affected
  dsa · starlette · debian · bookworm
- 0.26.1-1+deb12u2 · all · bookworm-security
  Not affected
  dsa · starlette · debian · bookworm
- 0.26.1-1+deb12u2 · all · bookworm-security
  Not affected
  dsa · starlette · debian · bookworm

[Debian 13 (Trixie)]

[python3-starlette]Fixed
Source package: [starlette]
Details (5)
- 0.46.1-3+deb13u2 · all · trixie
  Fixed · Fixed: 0.46.1-3+deb13u1
  dsa · starlette · debian · 13
- 0.46.1-3+deb13u2 · all · trixie
  Fixed · Fixed: 0.46.1-3+deb13u1
  dsa · starlette · debian · 13
- 0.46.1-3+deb13u2 · all · trixie-security · Historical version
  Fixed · Fixed: 0.46.1-3+deb13u1
  dsa · starlette · debian · 13
- 0.46.1-3+deb13u3 · all · trixie-security
  Fixed · Fixed: 0.46.1-3+deb13u1
  dsa · starlette · debian · 13
- 0.46.1-3+deb13u3 · all · trixie-security
  Fixed · Fixed: 0.46.1-3+deb13u1
  dsa · starlette · debian · 13

Observed: Oct 27, 2026, 11:16:49 AM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]