CVE catalog
CVE-2026-16434
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 prefix
- Severity
- Low · CVSS 2.3
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Published
- Updated
- Source
- [NVD] · [CVE record]
- EPSS
- 0.39% · Oct 25, 2026
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 REQUEST_URI and reaches cookie_path(), 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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | adminer | sid | 6.1.2-1 | fixed |
| Debian | adminer | forky | 6.1.0-1 | fixed |
| Debian | adminer | trixie | 5.2.1+dfsg-1 | vulnerable |
| Debian | adminer | bookworm | 4.8.1-1 | vulnerable |
| Ubuntu | adminer | pro | 4.7.2-1 | vulnerable |
| Ubuntu | adminer | pro | 4.7.4-1 | vulnerable |
| Ubuntu | adminer | pro | 4.7.5-1 | vulnerable |
| Ubuntu | adminer | pro | 4.7.6-1 | vulnerable |
| Ubuntu | adminer | pro | 4.7.6-1ubuntu0.1~esm1 | vulnerable |
| Ubuntu | adminer | 22.04 | 4.7.9-2 | vulnerable |
| Ubuntu | adminer | 22.04 | 4.8.1-1 | vulnerable |
| Ubuntu | adminer | 24.04 | 4.8.1-1 | vulnerable |
| Ubuntu | adminer | 24.04 | 4.8.1-1ubuntu1 | vulnerable |
| Ubuntu | adminer | 24.04 | 4.8.1-2 | vulnerable |
| Ubuntu | adminer | 26.04 | 5.2.1+dfsg-1 | vulnerable |
| Ubuntu | adminer | 26.04 | 5.3.0+dfsg-1 | vulnerable |
| Ubuntu | adminer | 26.04 | 5.4.0+dfsg-1 | vulnerable |
| Ubuntu | adminer | 26.04 | 5.4.1+dfsg-1 | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | adminer | source | sid | 6.0.0-1 | not yet assigned | Not reported | Not reported |
| Debian | adminer | source | forky | 6.0.0-1 | not yet assigned | Not reported | Not reported |
| Debian | adminer | source | trixie | (unfixed) | not yet assigned | Not reported | Not reported |
| Debian | adminer | source | bookworm | (unfixed) | not yet assigned | Not reported | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [adminer]Affected
Details (2)
4.8.1-1· all · bookwormAffected
nvd · adminer · debian · bookworm; nvd · adminer · debian · 12
4.8.1-1· all · bookwormAffected
nvd · adminer · debian · bookworm; nvd · adminer · debian · 12
[Debian 13 (Trixie)]
- [adminer]Affected
Details (2)
5.2.1+dfsg-1· all · trixieAffected
nvd · adminer · debian · 13
5.2.1+dfsg-1· all · trixieAffected
nvd · adminer · debian · 13
Observed:
References
- [https://nvd.nist.gov/vuln/detail/CVE-2026-16434]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-16434]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-16434]
- [https://security-tracker.debian.org/tracker/CVE-2026-16434]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database]