CVE-2026-45364

HIGHNVD 7.37.3
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

Score 7.3 from GitHub Security Advisory (severity: HIGH) published 2026-05-15. NVD baseline CVSS 7.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 3 sources updated this week

Also known asEUVD-2026-33073 (ENISA EUVD) · GHSA-p6v2-xcpg-h6xw (GitHub Security Advisories)Source: ENISA EUVD

7.3EG
EchelonGraph verdictPlan a fixRemediate 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: 7.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.4.17 and 1.5.0-beta.9, Better Auth's HTTP rate limiter keyed each request by the exact textual IP address it received in x-forwarded-for (or the configured IP-bearing header). IPv6 clients controlling a typical /64 allocation could rotate through 2^64 distinct source addresses without exhausting the per-address counter, defeating rate limiting on /sign-in/email, /sign-up/email, /forget-password, and every other path the limiter protects. The same bug allowed a single client to vary the textual encoding of one IPv6 address (uppercase, compression, IPv4-mapped, hex-encoded IPv4-in-IPv6) and produce multiple distinct keys. This vulnerability is fixed in 1.4.17 and 1.5.0-beta.9.

CVSS v3
7.3
EG Score
7.3HIGHmedium confidence
EG Risk
48
EG Risk 48/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity73% × 45%
Impact severity (EG Severity): CVSS 7.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.3% × 40%
FIRST EPSS: the 30-day exploitation probability 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 partial (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: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.3%
EPSS %ILE
22nd
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.3): severity, escalated by confirmed exploitation. This CVE's 7.3 is its impact severity (EG Severity), not escalated.

EG Severity
7.3 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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

May 15, 2026

Last Modified

July 21, 2026

Advisory Details (5)

Auto-updated May 29, 2026
Patch available. Sources: github, github_commit, github_pr.
GitHub advisoryMentions a patch (unverified)

Rate limiter keys IPv6 addresses individually and is bypassable via prefix rotation · Advisory · better-auth/better-auth · GitHub

https://github.com/better-auth/better-auth/security/advisories/GHSA-p6v2-xcpg-h6xw
GitHub pull request

fix: set default ipv6 subnet to 64

Fix merged in better-auth/better-auth PR #7509 on 2026-01-21 — awaiting tagged release

https://github.com/better-auth/better-auth/pull/7509
GitHub pull request Patch Available

fix(rate-limit): support IPv6 address normalization and subnet

Patch available: better-auth/better-auth v1.5.0 (PR #7470 merged 2026-01-19)

https://github.com/better-auth/better-auth/pull/7470
GitHub commit Patch Available

commit 57af0f7b910d (better-auth/better-auth)

Patch available: better-auth/better-auth v1.5.0 (contains commit 57af0f7b910d)

https://github.com/better-auth/better-auth/commit/57af0f7b910dcf7b1a5c0615d10b9bd56bb69bef
GitHub commit

commit 43e719bcc0c2 (better-auth/better-auth)

Fix landed in better-auth/better-auth commit 43e719bcc0c2 — awaiting tagged release

https://github.com/better-auth/better-auth/commit/43e719bcc0c223c7079fa0c611a9cf7ea1188254

Vendor Advisories for CVE-2026-45364(1)

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

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
npmbetter-auth @ 1.4.17 (fixes < 1.4.17)—ghsa
npmbetter-auth @ 1.5.0-beta.9 (fixes >= 1.5.0-beta.1, < 1.5.0-beta.9)—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFix by version rangeDependents
better-auth—
  • every version up to 1.4.17: fixed in 1.4.17
  • 1.5.0-beta.1 up to 1.5.0-beta.9: fixed in 1.5.0-beta.9
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 41× 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.

Showing the most recent 100 of 191 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 91 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  2. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  3. 2026-11-01 07:48 UTCGHSA enrichmentGHSA-p6v2-xcpg-h6xw · GitHub severity HIGH · GitHub CVSS 7.3
  4. 2026-11-01 07:48 UTCEG score recompute
  5. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  6. 2026-10-30 23:23 UTCEG score recompute
  7. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  8. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  9. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  10. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  11. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  12. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  13. 2026-10-25 14:26 UTCEG score recompute
  14. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  15. 2026-10-24 06:34 UTCEG score recompute
  16. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  17. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  18. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  19. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  20. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  21. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  22. 2026-10-18 03:38 UTCEG score recompute
  23. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  24. 2026-10-17 13:42 UTCEG score recompute
  25. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.5% · 41st percentile
Show 75 more
  1. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  2. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  3. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  4. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  5. 2026-10-12 16:04 UTCEG score recompute
  6. 2026-10-11 19:46 UTCEG score recompute
  7. 2026-10-11 17:01 UTCEG score recompute
  8. 2026-10-11 14:26 UTCEG score recompute
  9. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  10. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  11. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  12. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  13. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  14. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  15. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  16. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  17. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  18. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  19. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  20. 2026-09-30 04:28 UTCOSV refresh
  21. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  22. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  23. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  24. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  25. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  26. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  27. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  28. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  29. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  30. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  31. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  32. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  33. 2026-09-11 07:23 UTCOSV refresh
  34. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  35. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  36. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  37. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  38. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  39. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  40. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  41. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  42. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  43. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  44. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  45. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  46. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  47. 2026-08-23 17:28 UTCEG score recompute
  48. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  49. 2026-08-22 01:29 UTCEG score recompute
  50. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  51. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  52. 2026-08-20 19:24 UTCEG score recompute
  53. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  54. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  55. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  56. 2026-08-17 10:16 UTCEG score recompute
  57. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  58. 2026-08-16 03:49 UTCEG score recompute
  59. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  60. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  61. 2026-08-14 02:18 UTCEG score recompute
  62. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  63. 2026-08-12 14:51 UTCEG score recompute
  64. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  65. 2026-08-11 14:00 UTCEG score recompute
  66. 2026-08-11 00:48 UTCEG score recompute
  67. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  68. 2026-08-09 14:07 UTCEG score recompute
  69. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  70. 2026-08-09 01:45 UTCEG score recompute
  71. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  72. 2026-08-08 02:01 UTCEG score recompute
  73. 2026-08-07 01:17 UTCEG score recompute
  74. 2026-08-06 13:47 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  75. 2026-08-05 21:30 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-45364?
CVE-2026-45364 is a high-severity vulnerability; its CVE record was published on May 15, 2026. Better Auth is an authentication and authorization library for TypeScript. Prior to 1.4.17 and 1.5.0-beta.9, Better Auth's HTTP rate limiter keyed each request by the exact textual IP address it received in x-forwarded-for (or the configured IP-bearing header). IPv6 clients controlling a typical…
When was the CVE record for CVE-2026-45364 published?
The CVE record for CVE-2026-45364 was published on May 15, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 21, 2026; the record at its source may have been updated since.
Is CVE-2026-45364 actively exploited?
CVE-2026-45364 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (22nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-45364?
CVE-2026-45364 has a CVSS v3 base score of 7.3 (NVD).
How do I remediate CVE-2026-45364?
A fix for CVE-2026-45364 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-45364 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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