CVE Explorer

CVE-2025-62727

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.

Lifecycle PUBLISHED1 preserved revisionFact urn:baitaphish:canonical-cve-fact-revision:v2:64716c64c9d64b1fb2c603f913869646abe8482cf5fab1c363f3fd2857747ba4

Known exploited

Not asserted

Disputed

Stale source

Conflicts

Affected products and versions

1 source assertion

{"product":"starlette","vendor":"Kludex","versions":[{"status":"affected","version":">= 0.39.0, < 0.49.1"}]}

cve_program_cvelist_v5affected
urn:baitaphish:normalized-source-record:v2:bd5855760560f16076337e742b32cf8048befa90926228660a55f6d7a2d56c94 · sha256:1e52434c534efaf4… · /containers/cna/affected/0

Provider-owned CVSS observations

1 source assertion

{"metric":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"metric_type":"cvssV3_1"}

cve_program_cvelist_v5cvss
urn:baitaphish:normalized-source-record:v2:bd5855760560f16076337e742b32cf8048befa90926228660a55f6d7a2d56c94 · sha256:1e52434c534efaf4… · /containers/cna/metrics/0/cvssV3_1

CWE assertions

1 source assertion

{"cweId":"CWE-407","description":"CWE-407: Inefficient Algorithmic Complexity","lang":"en","type":"CWE"}

cve_program_cvelist_v5cwe
urn:baitaphish:normalized-source-record:v2:bd5855760560f16076337e742b32cf8048befa90926228660a55f6d7a2d56c94 · sha256:1e52434c534efaf4… · /containers/cna/problemTypes/0/descriptions/0

Source references

5 source assertions

{"name":"https://github.com/Kludex/starlette/commit/4ea6e22b489ec388d6004cfbca52dd5b147127c5","tags":["x_refsource_MISC"],"url":"https://github.com/Kludex/starlette/commit/4ea6e22b489ec388d6004cfbca52dd5b147127c5"}

cve_program_cvelist_v5reference
urn:baitaphish:normalized-source-record:v2:bd5855760560f16076337e742b32cf8048befa90926228660a55f6d7a2d56c94 · sha256:1e52434c534efaf4… · /containers/cna/references/1

{"name":"https://github.com/Kludex/starlette/commit/69ed26a85956ef4bd0161807eb27abf49be7cd3c","tags":["x_refsource_MISC"],"url":"https://github.com/Kludex/starlette/commit/69ed26a85956ef4bd0161807eb27abf49be7cd3c"}

cve_program_cvelist_v5reference
urn:baitaphish:normalized-source-record:v2:bd5855760560f16076337e742b32cf8048befa90926228660a55f6d7a2d56c94 · sha256:1e52434c534efaf4… · /containers/cna/references/2

{"name":"https://github.com/Kludex/starlette/releases/tag/0.49.1","tags":["x_refsource_MISC"],"url":"https://github.com/Kludex/starlette/releases/tag/0.49.1"}

cve_program_cvelist_v5reference
urn:baitaphish:normalized-source-record:v2:bd5855760560f16076337e742b32cf8048befa90926228660a55f6d7a2d56c94 · sha256:1e52434c534efaf4… · /containers/cna/references/3

{"name":"https://github.com/Kludex/starlette/security/advisories/GHSA-7f5h-v6xp-fcq8","tags":["x_refsource_CONFIRM"],"url":"https://github.com/Kludex/starlette/security/advisories/GHSA-7f5h-v6xp-fcq8"}

cve_program_cvelist_v5reference
urn:baitaphish:normalized-source-record:v2:bd5855760560f16076337e742b32cf8048befa90926228660a55f6d7a2d56c94 · sha256:1e52434c534efaf4… · /containers/cna/references/0

{"tags":["exploit"],"url":"https://github.com/Kludex/starlette/security/advisories/GHSA-7f5h-v6xp-fcq8"}

cve_program_cvelist_v5reference
urn:baitaphish:normalized-source-record:v2:bd5855760560f16076337e742b32cf8048befa90926228660a55f6d7a2d56c94 · sha256:1e52434c534efaf4… · /containers/adp/0/references/0

Attribution and limitations

CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →

Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.

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