Critical
undertow — security advisory
A flaw was found in Undertow. This vulnerability allows a remote attacker to construct specially crafted requests where header names are parsed differently by Undertow compared to upstream proxies. This discrepancy in header interpretation can be exploited to launch request smuggling attacks, potentially bypassing security controls and accessing unauthorized resources.
- Products
- undertow
- Affected versions
- 1.3.11-1, 1.3.16-1, 1.3.16-1ubuntu0.1~esm1, 1.3.4-1, 1.3.5-1, 1.3.7-1, 1.4.20-1, 1.4.21-1, 1.4.22-1, 1.4.23-1, 1.4.23-2build1, 1.4.23-3, 1.4.23-3ubuntu0.1~esm1, 2.0.23-1, 2.0.27-1, 2.0.28-1, 2.0.29-1, 2.0.29-1ubuntu0.1~esm1, 2.2.12-1, 2.2.13-1, 2.2.14-1, 2.2.16-1, 2.2.16-1ubuntu0.1~esm1, 2.2.8-1, 2.3.18-1, 2.3.18-2, 2.3.20-1, 2.3.20-1ubuntu1, 2.3.8-2, 2.3.8-2ubuntu0.1~esm1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-28368
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:06 UTC · Revision 1
Source evidence
A flaw was found in Undertow. This vulnerability allows a remote attacker to construct specially crafted requests where header names are parsed differently by Undertow compared to upstream proxies. This discrepancy in header interpretation can be exploited to launch request smuggling attacks, potentially bypassing security controls and accessing unauthorized resources.
osv:UBUNTU-CVE-2026-28368
undertow
Fixed versions: Not specified
undertow
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undertow
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undertow
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undertow
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undertow
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undertow
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undertow
Fixed versions: Not specified
Complete source record
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"modified": "2026-10-17T12:58:07.576472157Z",
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