CVE Explorer
CVE-2026-33523
HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers.
This issue affects Apache HTTP Server: from through 2.4.66.
Users are recommended to upgrade to version 2.4.67, which fixes the issue.
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0
Affected products and versions
1 source assertion{"defaultStatus":"unaffected","product":"Apache HTTP Server","vendor":"Apache Software Foundation","versions":[{"lessThanOrEqual":"2.4.66","status":"affected","version":"2.4.0","versionType":"semver"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:a9bf52ffb1e5f07bcf810dc521b8813e2b0e50682ec284e520cdc746e1fd65e4 · sha256:5ba3adcde46b72d4… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","version":"3.1"},"metric_type":"cvssV3_1"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:a9bf52ffb1e5f07bcf810dc521b8813e2b0e50682ec284e520cdc746e1fd65e4 · sha256:5ba3adcde46b72d4… · /containers/adp/0/metrics/0/cvssV3_1
CWE assertions
1 source assertion{"cweId":"CWE-443","description":"CWE-443: HTTP response splitting","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:a9bf52ffb1e5f07bcf810dc521b8813e2b0e50682ec284e520cdc746e1fd65e4 · sha256:5ba3adcde46b72d4… · /containers/cna/problemTypes/0/descriptions/0
Source references
2 source assertions{"url":"http://www.openwall.com/lists/oss-security/2026/05/04/23"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:a9bf52ffb1e5f07bcf810dc521b8813e2b0e50682ec284e520cdc746e1fd65e4 · sha256:5ba3adcde46b72d4… · /containers/adp/1/references/0
{"tags":["vendor-advisory"],"url":"https://httpd.apache.org/security/vulnerabilities_24.html"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:a9bf52ffb1e5f07bcf810dc521b8813e2b0e50682ec284e520cdc746e1fd65e4 · sha256:5ba3adcde46b72d4… · /containers/cna/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.