CVE-2026-91772

MEDIUMPre-NVD 6.16.1—
EchelonGraph scoreHIGH confidence

Score 6.1 from GitHub Security Advisory published 2026-09-15. a secondary CVSS source baseline 6.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this weekElevated
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.1Exploit: Elevated riskExposed: 0

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

Halo through 2.26.1 contains an open redirect vulnerability in the anonymous thumbnail endpoint that fails to validate the uri query parameter. Attackers can craft malicious links on the trusted Halo domain that redirect visitors to arbitrary external sites, enabling phishing attacks and abuse of redirect-based trust relationships.

CVSS v3
6.1
EG Score
6.1(high)
EG Risk
43(Track)
EG Risk 43/100SSVC: 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
Severity61% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
8%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 16, 2026

Advisory Details (5)

Auto-updated Sep 15, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic

Halo through 2.26.1 Open Redirect via Unvalidated URI Parameter | Advisories | VulnCheck

https://www.vulncheck.com/advisories/halo-through-2.26.1-open-redirect-via-unvalidated-uri-parameter
generic

GitHub - halo-dev/halo: Halo 是一款强大易用的开源建站工具，从个人博客、知识库，到企业官网、在线商城，Halo 都能助您轻松实现，一站式满足您的多样化建站需求。 · GitHub

https://github.com/halo-dev/halo
generic

halo/application/src/main/resources/extensions/role-template-anonymous.yaml at v2.26.1 · halo-dev/halo · GitHub

https://github.com/halo-dev/halo/blob/v2.26.1/application/src/main/resources/extensions/role-template-anonymous.yaml#L53-L55
generic

halo/application/src/main/java/run/halo/app/core/endpoint/theme/ThumbnailEndpoint.java at v2.26.1 · halo-dev/halo · GitHub

https://github.com/halo-dev/halo/blob/v2.26.1/application/src/main/java/run/halo/app/core/endpoint/theme/ThumbnailEndpoint.java#L76-L98
generic🟡 PoC Available

Unauthenticated Open Redirect via Thumbnail via-uri Endpoint (v2.25.1) · Issue #10247 · halo-dev/halo · GitHub

https://github.com/halo-dev/halo/issues/10247

Vendor Advisories for CVE-2026-91772(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 20× in last 7d / 20× 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. 2026-09-20 20:16 UTCEPSS rescore
  2. 2026-09-19 23:26 UTCEG score recompute
  3. 2026-09-19 23:26 UTCGHSA enrichment
  4. 2026-09-18 21:34 UTCEG score recompute
  5. 2026-09-18 21:34 UTCGHSA enrichment
  6. 2026-09-18 19:28 UTCEPSS rescore
  7. 2026-09-17 19:42 UTCEG score recompute
  8. 2026-09-17 19:42 UTCGHSA enrichment
  9. 2026-09-17 19:32 UTCEPSS rescore
  10. 2026-09-16 17:50 UTCEG score recompute
  11. 2026-09-16 17:49 UTCGHSA enrichment
  12. 2026-09-16 17:05 UTCEG score recompute
  13. 2026-09-16 17:05 UTCGHSA enrichment
  14. 2026-09-16 14:09 UTCEPSS rescore
  15. 2026-09-16 05:15 UTCEPSS rescore
  16. 2026-09-16 04:23 UTCEG score recompute
  17. 2026-09-16 04:23 UTCGHSA enrichment
  18. 2026-09-15 02:30 UTCEG score recompute
  19. 2026-09-15 01:40 UTCEG score recompute
  20. 2026-09-15 01:39 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-91772?
CVE-2026-91772 is a medium vulnerability published on September 15, 2026. Halo through 2.26.1 contains an open redirect vulnerability in the anonymous thumbnail endpoint that fails to validate the uri query parameter. Attackers can craft malicious links on the trusted Halo domain that redirect visitors to arbitrary external sites, enabling phishing attacks and abuse of…
When was CVE-2026-91772 disclosed?
CVE-2026-91772 was first published in the National Vulnerability Database on September 15, 2026, with the most recent update on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-91772 actively exploited?
CVE-2026-91772 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 91.8% of all scored CVEs.
What is the CVSS score of CVE-2026-91772?
CVE-2026-91772 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-91772?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-91772, 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-2026-91772

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