CVE-2026-63382

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Source
https://cve.org/CVERecord?id=CVE-2026-63382
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63382.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-63382
Aliases
  • GHSA-q39v-w2g7-gr8j
Downstream
Published
2026-08-20T17:51:15Z
Modified
2026-09-11T08:36:42Z
Severity
  • 9.2 (Critical) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:L/SI:L/SA:N CVSS Calculator
Summary
libevent evhttp: Multiple HTTP Parser Bugs Enable Request Smuggling
Details

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, the libevent evhttp parser in http.c inconsistently handles duplicate Transfer-Encoding headers, comma-separated Transfer-Encoding values, and bare line feeds in chunked framing. evhttp_find_header can select only the first header, evhttp_check_transfer_encoding_ was absent so the previous whole-string comparison fails to recognize valid lists ending in chunked, and evhttp_handle_chunked_read uses EVBUFFER_EOL_CRLF rather than EVBUFFER_EOL_CRLF_STRICT, accepting bare LF chunk terminators. When libevent is deployed behind a proxy that frames the same request differently, an unauthenticated remote attacker can desynchronize request boundaries and smuggle a second request, potentially bypassing access controls or poisoning caches. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-444"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63382.json"
}
References

Affected packages

Git / github.com/libevent/libevent

Affected ranges

Type
GIT
Repo
https://github.com/libevent/libevent
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
df3ecad3a040fd6d4fad4287defe113395de6fd7
Fixed
79ddfb460847999b807cba76d04e73891f29c6ee
Fixed
10abb34b8dc3e1184de315dd261ce4b77563cda6
Fixed
5119ceb00557bf007f9065709e852686f3c0bb6e
Fixed
83ba67373032334559b82409db035dd8c3cc1660
Fixed
ac38703b2d312200c4f967f02936af0118d384a0
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "2.2.0-alpha"
        },
        {
            "fixed": "2.2.2-alpha"
        },
        {
            "introduced": "0"
        },
        {
            "fixed": "2.1.13"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

release-1.*
release-1.1b
release-2.*
release-2.0.1-alpha
release-2.0.10-stable
release-2.0.3-alpha
release-2.0.4-alpha
release-2.0.5-beta
release-2.0.6-rc
release-2.0.7-rc
release-2.0.8-rc
release-2.0.9-rc
release-2.1.1-alpha
release-2.1.10-stable
release-2.1.11-stable
release-2.1.12-stable
release-2.1.2-alpha
release-2.1.3-alpha
release-2.1.4-alpha
release-2.1.5-beta
release-2.1.6-beta
release-2.1.7-rc
release-2.1.8-stable
release-2.1.9-beta
release-2.2.1-alpha

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63382.json"
vanir_signatures 
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vanir_signatures_modified 
"2026-09-11T08:36:42Z"