CVE-2026-77560

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6%, top 53% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this week
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.1Exploit: None knownExposed: 0

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

Tinyauth is an authentication and authorization server. Prior to 5.1.2, Tinyauth compares forwarded hostnames case-sensitively while reverse proxies route equivalent hostnames case-insensitively, allowing an authenticated low-privilege user to bypass per-app access controls with a differently cased hostname. The lookup in internal/service/access_controls_service.go through lookupStaticACLs and GetAccessControls, and the Docker-label fallback in internal/service/docker_service.go through GetLabels, can miss the configured app and return an empty access-control object. internal/controller/proxy_controller.go proxyHandler then treats the empty user, group, OAuth, LDAP, and IP restrictions as permissive and returns an authenticated result for an app that should exclude the user. Unauthenticated users remain subject to login, and global login-time allowlists are not bypassed. This issue is fixed in version 5.1.2.

CVSS v3
8.1
EG Score
8.1(medium)
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
Severity81% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
47%
KEV
Not listed

Published

September 21, 2026

Last Modified

September 24, 2026

Advisory Details (6)

Auto-updated Sep 21, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_pr, github_commit, github_release.
github_release Patch Available

v5.1.2

Patch available: tinyauthapp/tinyauth v5.1.2

https://github.com/tinyauthapp/tinyauth/releases/tag/v5.1.2
github_commit Patch Available

commit e75605b2c534 (tinyauthapp/tinyauth)

Patch available: tinyauthapp/tinyauth v5.1.0-rc.2 (contains commit e75605b2c534)

https://github.com/tinyauthapp/tinyauth/commit/e75605b2c534ec83525a33603e16d76baca13399
github_commit Patch Available

commit 80bc87188ec3 (tinyauthapp/tinyauth)

Patch available: tinyauthapp/tinyauth v5.1.2-beta.5 (contains commit 80bc87188ec3)

https://github.com/tinyauthapp/tinyauth/commit/80bc87188ec3aabc5104c249eaa7b997973b9275
github_pr Patch Available

refactor: rework acl fetching for kubernetes and docker

Patch available: tinyauthapp/tinyauth v5.1.2-beta.5 (PR #1028 merged 2026-07-20)

https://github.com/tinyauthapp/tinyauth/pull/1028
github_pr Patch Available

refactor: move domain check into small helper util

Patch available: tinyauthapp/tinyauth v5.1.0-rc.2 (PR #1000 merged 2026-07-14)

https://github.com/tinyauthapp/tinyauth/pull/1000
github Patch Available🟡 PoC Available

tinyauth: forward-auth per-app ACL is matched case-sensitively against the (case-insensitive) hostname, letting an authenticated user reach apps they are not on the allowlist for · Advisory · tinyauthapp/tinyauth · GitHub

https://github.com/tinyauthapp/tinyauth/security/advisories/GHSA-328g-jx67-v94g

Vendor Advisories for CVE-2026-77560(1)

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

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/tinyauthapp/tinyauth—1.0.1-0.20260720133915-80bc87188ec3—

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 11× 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. 2026-09-24 15:13 UTCEG score recompute
  2. 2026-09-24 14:04 UTCEPSS rescore
  3. 2026-09-24 04:15 UTCEG score recompute
  4. 2026-09-23 17:54 UTCEPSS rescore
  5. 2026-09-22 19:20 UTCEG score recompute
  6. 2026-09-22 16:01 UTCEPSS rescore
  7. 2026-09-21 21:23 UTCEG score recompute
  8. 2026-09-21 20:48 UTCEG score recompute
  9. 2026-09-21 17:25 UTCEG score recompute
  10. 2026-09-21 16:50 UTCEG score recompute
  11. 2026-09-21 16:50 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Same product

1 shown

Go:github.com/tinyauthapp/tinyauth

Frequently asked(5)

What is CVE-2026-77560?
CVE-2026-77560 is a high vulnerability published on September 21, 2026. Tinyauth is an authentication and authorization server. Prior to 5.1.2, Tinyauth compares forwarded hostnames case-sensitively while reverse proxies route equivalent hostnames case-insensitively, allowing an authenticated low-privilege user to bypass per-app access controls with a differently cased…
When was CVE-2026-77560 disclosed?
CVE-2026-77560 was first published in the National Vulnerability Database on September 21, 2026, with the most recent update on September 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-77560 actively exploited?
CVE-2026-77560 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 53.0% of all scored CVEs.
What is the CVSS score of CVE-2026-77560?
CVE-2026-77560 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-77560?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-77560, 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

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