CVE-2026-16434

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Source
https://cve.org/CVERecord?id=CVE-2026-16434
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-16434.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-16434
Aliases
  • GHSA-fr74-9mf9-gf44
Downstream
Published
2026-08-25T01:29:57.018Z
Modified
2026-08-28T03:30:32.792270004Z
Severity
  • 2.3 (Low) CVSS_V4 - CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N CVSS Calculator
Summary
Adminer before 5.5.1 X-Forwarded-Prefix Backslash Bypass
Details

Adminer 4.6.0 through 5.5.0 (fixed in 5.5.1) contains an incomplete fix for a prior X-Forwarded-Prefix vulnerability (GHSA-8478-xrj3-h9c2). The validation guard (bootstrap.inc.php) only rejects prefixes matching ^/[^/], blocking //evil.com but allowing values such as /\evil.com whose second character is a backslash. Because browsers normalize backslash to forward slash, a network-path reference survives into REQUESTURI and reaches cookiepath(), affecting the Set-Cookie Path attribute. Exploitation requires that clients can set the X-Forwarded-Prefix header (a misconfigured or absent reverse proxy). Impact is limited to anomalous cookie-path scoping.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/16xxx/CVE-2026-16434.json",
    "cwe_ids": [
        "CWE-20"
    ],
    "cna_assigner": "VulnCheck"
}
References

Affected packages

Git / github.com/vrana/adminer

Affected ranges

Type
GIT
Repo
https://github.com/vrana/adminer
Events
Introduced
d2ed0f7810e4f05a2fc6348286b622abf6464751
Fixed
be0b989473ec2b929f581234505aed487cbaa5a1
Database specific
Show details 
{
    "source": [
        "AFFECTED_FIELD",
        "DESCRIPTION"
    ],
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "5.5.1"
        },
        {
            "introduced": "4.6.0"
        },
        {
            "fixed": "5.5.0"
        }
    ]
}

Affected versions

v4.*
v4.16.0
v4.17.0
v4.17.1
v4.6.0
v4.6.1
v4.6.2
v4.6.3
v4.7.0
v4.7.1
v4.7.2
v4.7.3
v4.7.4
v4.7.5
v4.7.7
v4.7.8
v4.7.9
v4.8.0
v4.8.1
v5.*
v5.0.0
v5.0.1
v5.0.2
v5.0.3
v5.0.4
v5.0.5
v5.0.6
v5.1.0
v5.1.1
v5.2.0
v5.2.1
v5.3.0
v5.4.0
v5.4.1
v5.4.2
v5.4.3
v5.4.4
v5.5.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-16434.json"