CVE-2026-34959

MEDIUMPre-NVD 4.74.7—
EchelonGraph scoreHIGH confidence

Score 4.7 from GitHub Security Advisory published 2026-08-25. a secondary CVSS source baseline 4.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this weekElevated
4.7EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.7Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Adminer 4.6.0 before 5.5.0 prepends the client-supplied X-Forwarded-Prefix header to $_SERVER["REQUEST_URI"] with no trusted-proxy check and no validation of the prefix value. An attacker can supply an absolute URL (e.g. X-Forwarded-Prefix: https://evil.example) that flows into Location redirect headers, the Set-Cookie path attribute, and self-referential links. This enables an authenticated open redirect after state-changing POSTs, unauthenticated control of the session cookie path attribute, and poisoning of self-referential links; CR/LF cannot be injected, so header splitting/XSS is not possible.

CVSS v3
4.7
EG Score
4.7(high)
EG Risk
37(Track)
EG Risk 37/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity47% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
11%
KEV
Not listed

Published

August 25, 2026

Last Modified

August 26, 2026

Advisory Details (2)

Auto-updated Aug 25, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

Adminer before 5.5.0 Open Redirect via X-Forwarded-Prefix | Advisories | VulnCheck

https://www.vulncheck.com/advisories/adminer-before-open-redirect-via-x-forwarded-prefix
github Patch Available🟡 PoC Available

X-Forwarded-Prefix open redirect · Advisory · vrana/adminer · GitHub

https://github.com/vrana/adminer/security/advisories/GHSA-8478-xrj3-h9c2

Vendor Advisories for CVE-2026-34959(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 19× in last 7d / 19× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 20:51 UTCEG score recompute
  3. 2026-08-29 20:51 UTCGHSA enrichment
  4. 2026-08-28 21:41 UTCEPSS rescore
  5. 2026-08-28 19:32 UTCGHSA enrichment
  6. 2026-08-27 18:12 UTCEG score recompute
  7. 2026-08-27 18:11 UTCGHSA enrichment
  8. 2026-08-27 14:25 UTCEPSS rescore
  9. 2026-08-26 15:59 UTCEG score recompute
  10. 2026-08-26 15:59 UTCGHSA enrichment
  11. 2026-08-26 14:46 UTCEPSS rescore
  12. 2026-08-26 14:24 UTCEG score recompute
  13. 2026-08-26 14:24 UTCGHSA enrichment
  14. 2026-08-26 03:39 UTCEG score recompute
  15. 2026-08-26 03:39 UTCGHSA enrichment
  16. 2026-08-25 13:49 UTCEPSS rescore
  17. 2026-08-25 02:19 UTCEG score recompute
  18. 2026-08-25 01:50 UTCEG score recompute
  19. 2026-08-25 01:50 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-34959?
CVE-2026-34959 is a medium vulnerability published on August 25, 2026. Adminer 4.6.0 before 5.5.0 prepends the client-supplied X-Forwarded-Prefix header to $SERVER["REQUESTURI"] with no trusted-proxy check and no validation of the prefix value. An attacker can supply an absolute URL (e.g. X-Forwarded-Prefix: https://evil.example) that flows into Location redirect…
When was CVE-2026-34959 disclosed?
CVE-2026-34959 was first published in the National Vulnerability Database on August 25, 2026, with the most recent update on August 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-34959 actively exploited?
CVE-2026-34959 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 89.2% of all scored CVEs.
What is the CVSS score of CVE-2026-34959?
CVE-2026-34959 has a CVSS v3 base score of 4.7 (NVD).
How do I remediate CVE-2026-34959?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-34959, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-34959

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