CVE-2026-64647

MEDIUMNVD 5.45.4
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 5.4 under NVD CVSS v3. EPSS exploit probability: 0.3% (24th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
Trending — 3 sources updated this week

Also known asEUVD-2026-49404 (ENISA EUVD) · GHSA-4633-3j49-mh5q (GitHub Security Advisories)Source: ENISA EUVD

5.4EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 5.4Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, a server-side fetch with a request body may return a cached response body from a different request to the same URL but different body. Confidential data in the POST's response body would then leak to unauthorized requests. Though the request itself will not be deduped. This is only an issue when receiving request bodies with a content type charset other than UTF-8. For example, the UTF-16 byte sequences for 삃삃 and 섄섄 in the request body would share the same cache. This issue has been fixed in versions 15.5.21 and 16.2.11.

CVSS v3
5.4
EG Score
5.4MEDIUMmedium confidence
EG Risk
24
EG Risk 24/100

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)
Severity54% × 45%
Impact severity (EG Severity): CVSS 5.4 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.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (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.
EPSS PROB
0.3%
EPSS %ILE
24th
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 (5.4): severity, escalated by confirmed exploitation. This CVE's 5.4 is its impact severity (EG Severity), not escalated.

EG Severity
5.4 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
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 every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade 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 every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (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

July 22, 2026

Last Modified

October 24, 2026

Advisory Details (5)

Auto-updated Jul 27, 2026
Patch available. Sources: github_pr, github_release, github, github_commit.
GitHub advisoryMentions a patch (unverified)

Cache confusion of response bodies for requests with bodies containing invalid UTF-8 byte sequences · Advisory · vercel/next.js · GitHub

https://github.com/vercel/next.js/security/advisories/GHSA-4633-3j49-mh5q
GitHub release Patch Available

v16.2.11

Patch available: vercel/next.js v16.2.11

https://github.com/vercel/next.js/releases/tag/v16.2.11
GitHub release Patch Available

v15.5.21

Patch available: vercel/next.js v15.5.21

https://github.com/vercel/next.js/releases/tag/v15.5.21
GitHub pull request Patch Available

fix(incremental-cache): byte-exact fetch cache key for binary bodies

Patch available: vercel/next.js v16.3.0-canary.92 (PR #96008 merged 2026-07-21)

https://github.com/vercel/next.js/pull/96008
GitHub commit Patch Available

commit 025bf4a5f7b4 (vercel/next.js)

Patch available: vercel/next.js v16.3.0-canary.92 (contains commit 025bf4a5f7b4)

https://github.com/vercel/next.js/commit/025bf4a5f7b47fb7758c4ebf1c931a61c451c082

Vendor Advisories for CVE-2026-64647(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
npmnext @ 15.5.21 (fixes >= 13.0.0, < 15.5.21)—ghsa
npmnext @ 16.2.11 (fixes >= 16.0.0, < 16.2.11)—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
next—
  • 13.0.0 up to 15.5.21: fixed in 15.5.21
  • 16.0.0 up to 16.2.11: fixed in 16.2.11
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 42× 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 146 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 46 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  2. 2026-11-01 07:40 UTCGHSA enrichmentGHSA-4633-3j49-mh5q · GitHub severity MODERATE
  3. 2026-11-01 07:40 UTCEG score recompute
  4. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  5. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  6. 2026-10-29 16:41 UTCEG score recompute
  7. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  8. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  9. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  10. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  11. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  12. 2026-10-25 14:12 UTCEG score recompute
  13. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  14. 2026-10-24 13:33 UTCEG score recompute
  15. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  16. 2026-10-22 19:43 UTCEG score recompute
  17. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  18. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  19. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  20. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  21. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  22. 2026-10-18 03:22 UTCEG score recompute
  23. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  24. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  25. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
Show 75 more
  1. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  2. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  3. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  4. 2026-10-12 15:47 UTCEG score recompute
  5. 2026-10-11 19:32 UTCEG score recompute
  6. 2026-10-11 16:47 UTCEG score recompute
  7. 2026-10-11 14:08 UTCEG score recompute
  8. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  9. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  11. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  12. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  13. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  14. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  15. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  16. 2026-10-04 12:45 UTCEG score recompute
  17. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  18. 2026-10-03 03:31 UTCEG score recompute
  19. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  20. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  21. 2026-10-01 06:26 UTCEG score recompute
  22. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  23. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  24. 2026-09-28 05:14 UTCEG score recompute
  25. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  26. 2026-09-24 01:30 UTCEG score recompute
  27. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  28. 2026-09-22 23:00 UTCEG score recompute
  29. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  30. 2026-09-20 01:58 UTCEG score recompute
  31. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  32. 2026-09-18 09:47 UTCEG score recompute
  33. 2026-09-17 09:36 UTCEG score recompute
  34. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  35. 2026-09-16 06:55 UTCEG score recompute
  36. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  37. 2026-09-13 22:25 UTCEG score recompute
  38. 2026-09-12 21:12 UTCEG score recompute
  39. 2026-09-11 21:12 UTCEG score recompute
  40. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  41. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  42. 2026-09-10 21:12 UTCEG score recompute
  43. 2026-09-09 09:11 UTCEG score recompute
  44. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  45. 2026-09-07 21:39 UTCEG score recompute
  46. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  47. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  48. 2026-09-05 19:33 UTCEG score recompute
  49. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  50. 2026-09-04 13:39 UTCEG score recompute
  51. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  52. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  53. 2026-09-01 23:30 UTCEG score recompute
  54. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  55. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  56. 2026-08-31 00:48 UTCEG score recompute
  57. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  58. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  59. 2026-08-30 00:48 UTCEG score recompute
  60. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  61. 2026-08-27 21:17 UTCEG score recompute
  62. 2026-08-26 21:17 UTCEG score recompute
  63. 2026-08-26 14:47 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  64. 2026-08-25 20:48 UTCEG score recompute
  65. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  66. 2026-08-24 20:41 UTCEG score recompute
  67. 2026-08-23 20:42 UTCEG score recompute
  68. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  69. 2026-08-22 20:42 UTCEG score recompute
  70. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  71. 2026-08-21 20:42 UTCEG score recompute
  72. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  73. 2026-08-19 20:41 UTCEG score recompute
  74. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  75. 2026-08-18 19:09 UTCEG score recompute

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Frequently asked(5)

What is CVE-2026-64647?
CVE-2026-64647 is a medium-severity vulnerability; its CVE record was published on July 22, 2026. Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, a server-side fetch with a request body may return a cached response body from a different request to the same URL but different body. Confidential data in the…
When was the CVE record for CVE-2026-64647 published?
The CVE record for CVE-2026-64647 was published on July 22, 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 October 24, 2026; the record at its source may have been updated since.
Is CVE-2026-64647 actively exploited?
CVE-2026-64647 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (24th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-64647?
CVE-2026-64647 has a CVSS v3 base score of 5.4 (NVD).
How do I remediate CVE-2026-64647?
A fix for CVE-2026-64647 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-64647 are linked in the Vendor Advisories panel on this page.

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