CVE-2026-47774

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 1.0% (62nd percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source

Also known asEUVD-2026-37765 (ENISA EUVD)Source: ENISA EUVD

7.5EG
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: 1.0%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.35.11, 1.36.7, 1.37.3, and 1.38.1, a vulnerability in Envoy's HTTP/2 downstream request processing allows an unauthenticated remote client to trigger excessive memory consumption, potentially resulting in OOM termination of the Envoy process and denial of service. The issue arises from the combination of two behaviors. First, cookie header bytes are not fully accounted for during request header size validation in Envoy. Second, HPACK header block limits in oghttp2/quiche are enforced on encoded bytes without a corresponding limit on total decoded header size. Together, these behaviors allow a malicious client to cause large decoded header allocations while bypassing the intended request header size protections. Versions 1.35.11, 1.36.7, 1.37.3, and 1.38.1 contain a fix. No complete workaround is known short of applying a fix. Possible temporary mitigations include disabling downstream HTTP/2 where operationally feasible; enforcing stricter request header and cookie limits before traffic reaches Envoy; and monitoring Envoy memory usage for abnormal growth under HTTP/2 traffic.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
49
EG Risk 49/100

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)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation1.0% × 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
1.0%
EPSS %ILE
62nd
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 (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
1.0% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-08). 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

June 17, 2026

Last Modified

October 26, 2026

Advisory Details (2)

Auto-updated Jun 17, 2026
Patch available. Sources: github.
Web page

oss-security - Re: HTTP/2 Bomb affects Apache httpd, nginx, envoy, & pingora

http://www.openwall.com/lists/oss-security/2026/06/04/15
GitHub advisoryMentions a patch (unverified)

HTTP/2 memory exhaustion via cookie header size bypass and HPACK amplification · Advisory · envoyproxy/envoy · GitHub

https://github.com/envoyproxy/envoy/security/advisories/GHSA-22m2-hvr2-xqc8

Patch Availability(5)

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.

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 34× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 290 rows 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 190 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:52 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  2. 2026-11-12 16:34 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  3. 2026-11-11 16:39 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  4. 2026-11-10 16:44 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  5. 2026-11-09 16:35 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  6. 2026-11-08 19:39 UTCEchelonGraph re-scored
  7. 2026-11-08 19:39 UTCVendor advisory
  8. 2026-11-08 16:39 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  9. 2026-11-07 16:39 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  10. 2026-11-06 16:38 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  11. 2026-11-05 16:37 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  12. 2026-11-04 16:35 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  13. 2026-11-03 16:48 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  14. 2026-11-02 16:45 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  15. 2026-11-02 03:34 UTCEchelonGraph re-scored
  16. 2026-11-02 03:34 UTCVendor advisory
  17. 2026-10-31 16:32 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  18. 2026-10-30 16:34 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  19. 2026-10-29 16:33 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  20. 2026-10-28 16:32 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  21. 2026-10-27 16:32 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  22. 2026-10-26 16:31 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  23. 2026-10-26 11:28 UTCEchelonGraph re-scored
  24. 2026-10-26 11:28 UTCVendor advisory
  25. 2026-10-25 16:33 UTCEPSS rescoreEPSS 1.0% · 61st percentile
Show 75 more
  1. 2026-10-25 14:24 UTCEchelonGraph re-scored
  2. 2026-10-24 16:33 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  3. 2026-10-24 04:49 UTCEchelonGraph re-scored
  4. 2026-10-24 04:49 UTCVendor advisory
  5. 2026-10-23 16:32 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  6. 2026-10-22 16:34 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  7. 2026-10-21 16:33 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  8. 2026-10-20 16:33 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  9. 2026-10-19 16:32 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  10. 2026-10-18 16:32 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  11. 2026-10-18 03:35 UTCEchelonGraph re-scored
  12. 2026-10-17 16:34 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  13. 2026-10-17 12:38 UTCEchelonGraph re-scored
  14. 2026-10-17 12:38 UTCVendor advisory
  15. 2026-10-16 16:42 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  16. 2026-10-15 16:32 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  17. 2026-10-14 16:33 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  18. 2026-10-13 16:34 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  19. 2026-10-12 16:34 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  20. 2026-10-12 16:01 UTCEchelonGraph re-scored
  21. 2026-10-11 19:44 UTCEchelonGraph re-scored
  22. 2026-10-11 16:59 UTCEchelonGraph re-scored
  23. 2026-10-11 14:23 UTCEchelonGraph re-scored
  24. 2026-10-11 13:48 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  25. 2026-10-10 20:00 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  26. 2026-10-09 20:07 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  27. 2026-10-08 17:12 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  28. 2026-10-07 23:48 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  29. 2026-10-06 15:18 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  30. 2026-10-05 17:43 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  31. 2026-10-04 23:22 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  32. 2026-10-03 14:25 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  33. 2026-10-03 06:09 UTCOSV refresh
  34. 2026-10-01 19:50 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  35. 2026-09-30 15:03 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  36. 2026-09-28 13:51 UTCEPSS rescoreEPSS 1.1% · 62nd percentile
  37. 2026-09-27 13:48 UTCEPSS rescoreEPSS 1.1% · 62nd percentile
  38. 2026-09-26 15:59 UTCEPSS rescoreEPSS 1.1% · 62nd percentile
  39. 2026-09-26 00:27 UTCEPSS rescoreEPSS 1.1% · 62nd percentile
  40. 2026-09-23 17:53 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  41. 2026-09-20 20:16 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  42. 2026-09-18 19:28 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  43. 2026-09-16 14:08 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  44. 2026-09-16 05:15 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  45. 2026-09-14 03:15 UTCEchelonGraph re-scored
  46. 2026-09-14 03:15 UTCVendor advisory
  47. 2026-09-13 16:47 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  48. 2026-09-13 14:12 UTCEchelonGraph re-scored
  49. 2026-09-13 14:12 UTCVendor advisory
  50. 2026-09-11 14:53 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  51. 2026-09-10 09:35 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  52. 2026-09-08 22:00 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  53. 2026-09-07 16:01 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  54. 2026-09-06 13:47 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  55. 2026-09-04 05:06 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  56. 2026-09-02 14:12 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  57. 2026-09-01 13:54 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  58. 2026-08-30 21:19 UTCEchelonGraph re-scored
  59. 2026-08-30 21:19 UTCVendor advisory
  60. 2026-08-30 19:17 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  61. 2026-08-30 01:22 UTCEPSS rescoreEPSS 1.0% · 58th percentile
  62. 2026-08-28 21:41 UTCEPSS rescoreEPSS 1.0% · 58th percentile
  63. 2026-08-27 14:25 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  64. 2026-08-26 14:46 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  65. 2026-08-25 13:49 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  66. 2026-08-25 01:30 UTCEchelonGraph re-scored
  67. 2026-08-25 01:30 UTCVendor advisory
  68. 2026-08-24 12:20 UTCEchelonGraph re-scored
  69. 2026-08-24 12:20 UTCVendor advisory
  70. 2026-08-24 06:50 UTCVendor advisory
  71. 2026-08-23 17:16 UTCVendor advisory
  72. 2026-08-23 04:12 UTCEchelonGraph re-scored
  73. 2026-08-23 04:12 UTCVendor advisory
  74. 2026-08-23 00:19 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  75. 2026-08-21 23:49 UTCEPSS rescoreEPSS 1.0% · 59th percentile

Frequently asked(5)

What is CVE-2026-47774?
CVE-2026-47774 is a high-severity vulnerability; its CVE record was published on June 17, 2026. Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.35.11, 1.36.7, 1.37.3, and 1.38.1, a vulnerability in Envoy's HTTP/2 downstream request processing allows an unauthenticated remote client to trigger excessive memory consumption, potentially…
When was the CVE record for CVE-2026-47774 published?
The CVE record for CVE-2026-47774 was published on June 17, 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 26, 2026; the record at its source may have been updated since.
Is CVE-2026-47774 actively exploited?
CVE-2026-47774 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.0% probability of exploitation in the next 30 days (62nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-47774?
CVE-2026-47774 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-47774?
A fix for CVE-2026-47774 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-47774 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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