Better Auth from 1.4.0-beta.18 before 1.7.7 contains an authentication bypass vulnerability that allows unauthenticated attackers to sign in as other users by reusing OAuth state values as Magic Link tokens. Attackers can start an OAuth sign-in with a victim's email and submit the returned state to Magic Link verification, gaining sessions or creating falsely email-verified accounts.
CVE-2026-110862
CRITICALPre-NVD 9.19.1Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
“—” beside the score: it is equal to the CVSS score beside it.
Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-10-15. A secondary CVSS source baseline 9.1; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: GitHub Security Advisory, a secondary CVSS source
9.1EG
EchelonGraph verdictPlan mitigationRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 9.1Exploit: None knownExposed services: Not assessed
No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.
The CVE record's CNA (VulnCheck) lists better-auth versions 1.4.0-beta.18 up to but not including 1.7.7 as affected, and better-auth versions 1.7.7 as unaffected. No release containing a fix is confirmed on record.
- CVSS v3
- 9.1
- EG Score
- 9.1CRITICALhigh confidence
- EG Risk
- 56EG Risk 56/100
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 (value × EchelonGraph’s weight)Severity91% × 45%The EG Score, 9.1 of 10.Exploitation0% × 40%No KEV listing, EG-KEV tier or EPSS when EchelonGraph scored this CVE.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix. - EPSS PROB
- 0.3%
- EPSS %ILE
- 23rd
- KEV
- Not listed
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).
No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 60 days if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
October 14, 2026
Last Modified
October 15, 2026
Advisory Details (2)
Auto-updated Oct 14, 2026No fix on record yet. Sources: github.
Web page
Better Auth 1.4.0-beta.18 before 1.7.7 Authentication Bypass via Magic Link | Advisories | VulnCheck
https://www.vulncheck.com/advisories/better-auth-1.4.0-beta.18-before-1.7.7-authentication-bypass-via-magic-linkGitHub advisoryMentions a patch (unverified)
better-auth: OAuth state can be used as a Magic Link to sign in as another user · Advisory · better-auth/better-auth · GitHub
https://github.com/better-auth/better-auth/security/advisories/GHSA-965c-763c-88jmVendor Advisories for CVE-2026-110862(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 8× in last 7d / 8× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
- 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
- 2026-10-15 14:28 UTCEG score recompute
- 2026-10-15 14:27 UTCGHSA enrichmentGHSA-p7w7-v3vp-w8x8 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-15 13:39 UTCEG score recompute
- 2026-10-15 13:39 UTCGHSA enrichmentGHSA-p7w7-v3vp-w8x8 · GitHub severity CRITICAL · GitHub CVSS 9.1
- 2026-10-14 23:27 UTCEG score recompute
- 2026-10-14 22:55 UTCEG score recomputeFirst assessed: 9.1 CRITICAL
- 2026-10-14 22:53 UTCMITRE cvelistV5first tracked
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Frequently asked(5)
What is CVE-2026-110862?
CVE-2026-110862 is a critical-severity vulnerability; its CVE record was published on October 14, 2026. Better Auth from 1.4.0-beta.18 before 1.7.7 contains an authentication bypass vulnerability that allows unauthenticated attackers to sign in as other users by reusing OAuth state values as Magic Link tokens. Attackers can start an OAuth sign-in with a victim's email and submit the returned state to…
When was CVE-2026-110862 made public?
CVE-2026-110862 was made public on September 30, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on October 14, 2026. EchelonGraph's copy of the record carries a last-modified date of October 15, 2026; the record at its source may have been updated since.
Is CVE-2026-110862 actively exploited?
CVE-2026-110862 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (23rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-110862?
CVE-2026-110862 has a CVSS base score of 9.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-110862?
No fix for CVE-2026-110862 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The CVE record's CNA (VulnCheck) lists better-auth versions 1.4.0-beta.18 up to but not including 1.7.7 as affected, and better-auth versions 1.7.7 as unaffected. No release containing a fix is confirmed on record. The vendor advisories EchelonGraph has for CVE-2026-110862 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
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