High
gunicorn — security advisory
Gunicorn fails to properly validate Transfer-Encoding headers, leading to HTTP Request Smuggling (HRS) vulnerabilities. By crafting requests with conflicting Transfer-Encoding headers, attackers can bypass security restrictions and access restricted endpoints. This issue is due to Gunicorn's handling of Transfer-Encoding headers, where it incorrectly processes requests with multiple, conflicting Transfer-Encoding headers, treating them as chunked regardless of the final encoding specified. This vulnerability allows for a range of attacks including cache poisoning, session manipulation, and data exposure.
- Products
- gunicorn
- Affected versions
- 17.5-2, 17.5-2build1, 17.5-2ubuntu0.1~esm1, 19.0-8ubuntu1, 19.4.1-1ubuntu1, 19.4.5-1ubuntu1, 19.4.5-1ubuntu1.1, 19.7.1-3, 19.7.1-4, 19.9.0-1, 19.9.0-4, 20.0.0-1, 20.0.2-1, 20.0.4-1, 20.0.4-2, 20.0.4-3, 20.1.0-1, 20.1.0-2, 20.1.0-6, 20.1.0-6ubuntu0.1, 23.0.0-1, 23.0.0-1build1, 25.0.3-2, 25.1.0-1, 25.3.0-2, 25.3.0-3, 25.3.0-4
- Fixed versions
- Not specified
- CVEs
- CVE-2024-1135
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 01:06 UTC · Revision 1
Source evidence
Gunicorn fails to properly validate Transfer-Encoding headers, leading to HTTP Request Smuggling (HRS) vulnerabilities. By crafting requests with conflicting Transfer-Encoding headers, attackers can bypass security restrictions and access restricted endpoints. This issue is due to Gunicorn's handling of Transfer-Encoding headers, where it incorrectly processes requests with multiple, conflicting Transfer-Encoding headers, treating them as chunked regardless of the final encoding specified. This vulnerability allows for a range of attacks including cache poisoning, session manipulation, and data exposure.
osv:UBUNTU-CVE-2024-1135
gunicorn
Fixed versions: Not specified
gunicorn
Fixed versions: Not specified
gunicorn
Fixed versions: Not specified
gunicorn
Fixed versions: Not specified
gunicorn
Fixed versions: Not specified
gunicorn
Fixed versions: Not specified
gunicorn
Fixed versions: Not specified
gunicorn
Fixed versions: Not specified
gunicorn
Fixed versions: Not specified
Complete source record
{
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"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2024-1135",
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"summary": "Gunicorn fails to properly validate Transfer-Encoding headers, leading to HTTP Request Smuggling (HRS) vulnerabilities. By crafting requests with conflicting Transfer-Encoding headers, attackers can bypass security restrictions and access restricted endpoints. This issue is due to Gunicorn's handling of Transfer-Encoding headers, where it incorrectly processes requests with multiple, conflicting Transfer-Encoding headers, treating them as chunked regardless of the final encoding specified. This vulnerability allows for a range of attacks including cache poisoning, session manipulation, and data exposure.",
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"modified": "2026-10-17T12:56:29.103618958Z",
"provider": "osv",
"upstream": [
"CVE-2024-1135"
],
"references": [
"https://ubuntu.com/security/CVE-2024-1135",
"https://www.cve.org/CVERecord?id=CVE-2024-1135",
"https://huntr.com/bounties/22158e34-cfd5-41ad-97e0-a780773d96c1",
"https://github.com/benoitc/gunicorn/commit/ac29c9b0a758d21f1e0fb3b3457239e523fa9f1d"
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},
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"value": "CVE-2024-1135",
"evidence": "/upstream"
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],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 355723,
"published_at": "2024-04-16T00:15:00+00:00"
}