CVE-2025-55315

CRITICALNVD 9.99.9
EchelonGraph scoreMEDIUM confidence

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

This critical-severity CVE scores 9.9 under NVD CVSS v3. EPSS exploit probability: 67% (99th 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 weekWeaponized

Also known asEUVD-2025-34426 (ENISA EUVD)Source: ENISA EUVD

9.9EG
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 exploitation likelihood — EPSS 67%
  • Public exploit or proof-of-concept code is available
CISA-KEV: Not listedEPSS PROB: 67%CVSS: 9.9Exploit: Public PoCExposed services: Not assessed

A fix is available — apply it.

Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows an authorized attacker to bypass a security feature over a network.

CVSS v3
9.9
EG Score
9.9CRITICALmedium confidence
EG Risk
71
EG Risk 71/100

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)
Severity99% × 45%
Impact severity (EG Severity): CVSS 9.9 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation67% × 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 low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (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: 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
67%
EPSS %ILE
99th
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 (9.9): severity, escalated by confirmed exploitation. This CVE's 9.9 is its impact severity (EG Severity), not escalated.

EG Severity
9.9 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
67% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-29). 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, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

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

Exploitation public PoC (CISA Vulnrichment) · Automatable no (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)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (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, 2025

Last Modified

October 18, 2026

Advisory Details (3)

Auto-updated Oct 26, 2026
🔬 Proof of concept available. Patch available. Sources: microsoft.
Web page🟡 PoC Available

Kestrel Chunked Smuggling Proof of Concept (CVE-2025-55315) · GitHub

https://gist.github.com/N3mes1s/d0897c13ca199e739ecc2b562f466040
Web page

Understanding the worst .NET vulnerability ever: request smuggling and CVE-2025-55315

https://andrewlock.net/understanding-the-worst-dotnet-vulnerability-request-smuggling-and-cve-2025-55315/
Microsoft

Security Update Guide - Microsoft Security Response Center

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-55315

Patch Availability(13)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntunetstandard-targeting-pack-2.1-8.0 (8.0.121-0ubuntu1~22.04.1) @ jammy2026-10-29ubuntu
redhatdotnet9-0-main-9.0.116-1.hum12026-04-21redhat
redhatdotnet8-0-main-8.0.126-1.hum12026-04-20redhat
redhatdevspaces/udi-rhel9:3.25.0-17655822072025-12-15redhat
redhatdotnet10.0-0:10.0.100~rc.2.25502.107-0.10.el9_72025-11-11redhat
redhatdotnet10.0-0:10.0.100~rc.2.25502.107-0.12.el10_12025-11-11redhat
redhatdotnet8.0-0:8.0.121-1.el9_42025-10-16redhat
redhatdotnet9.0-0:9.0.111-1.el8_102025-10-15redhat
redhatdotnet8.0-0:8.0.121-1.el9_62025-10-15redhat
redhatdotnet9.0-0:9.0.111-1.el10_02025-10-15redhat
redhatdotnet8.0-0:8.0.121-1.el8_102025-10-15redhat
redhatdotnet9.0-0:9.0.111-1.el9_62025-10-15redhat
redhatdotnet8.0-0:8.0.121-1.el10_02025-10-15redhat

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

(13 across 1 ecosystem)
NuGet(13)
PackageVulnerable rangeFix by version rangeDependents
Microsoft.AspNetCore.App.Runtime.linux-arm8.0.0 ... 8.0.8 (20 versions)
  • 10.0.0-rc.1.25451.107 up to 10.0.0-rc.2.25502.107: fixed in 10.0.0-rc.2.25502.107
  • 9.0.0 up to 9.0.10: fixed in 9.0.10
  • 8.0.0 up to 8.0.21: fixed in 8.0.21
—
Microsoft.AspNetCore.App.Runtime.linux-arm648.0.0 ... 8.0.8 (20 versions)
  • 10.0.0-rc.1.25451.107 up to 10.0.0-rc.2.25502.107: fixed in 10.0.0-rc.2.25502.107
  • 9.0.0 up to 9.0.10: fixed in 9.0.10
  • 8.0.0 up to 8.0.21: fixed in 8.0.21
—
Microsoft.AspNetCore.App.Runtime.linux-musl-arm8.0.0 ... 8.0.8 (20 versions)
  • 10.0.0-rc.1.25451.107 up to 10.0.0-rc.2.25502.107: fixed in 10.0.0-rc.2.25502.107
  • 9.0.0 up to 9.0.10: fixed in 9.0.10
  • 8.0.0 up to 8.0.21: fixed in 8.0.21
—
Microsoft.AspNetCore.App.Runtime.linux-musl-arm648.0.0 ... 8.0.8 (20 versions)
  • 10.0.0-rc.1.25451.107 up to 10.0.0-rc.2.25502.107: fixed in 10.0.0-rc.2.25502.107
  • 9.0.0 up to 9.0.10: fixed in 9.0.10
  • 8.0.0 up to 8.0.21: fixed in 8.0.21
—
Microsoft.AspNetCore.App.Runtime.linux-musl-x648.0.0 ... 8.0.8 (20 versions)
  • 10.0.0-rc.1.25451.107 up to 10.0.0-rc.2.25502.107: fixed in 10.0.0-rc.2.25502.107
  • 9.0.0 up to 9.0.10: fixed in 9.0.10
  • 8.0.0 up to 8.0.21: fixed in 8.0.21
—
Microsoft.AspNetCore.App.Runtime.linux-x648.0.0 ... 8.0.8 (20 versions)
  • 10.0.0-rc.1.25451.107 up to 10.0.0-rc.2.25502.107: fixed in 10.0.0-rc.2.25502.107
  • 9.0.0 up to 9.0.10: fixed in 9.0.10
  • 8.0.0 up to 8.0.21: fixed in 8.0.21
—
Microsoft.AspNetCore.App.Runtime.osx-arm648.0.0 ... 8.0.8 (20 versions)
  • 10.0.0-rc.1.25451.107 up to 10.0.0-rc.2.25502.107: fixed in 10.0.0-rc.2.25502.107
  • 9.0.0 up to 9.0.10: fixed in 9.0.10
  • 8.0.0 up to 8.0.21: fixed in 8.0.21
—
Microsoft.AspNetCore.App.Runtime.osx-x648.0.0 ... 8.0.8 (20 versions)
  • 10.0.0-rc.1.25451.107 up to 10.0.0-rc.2.25502.107: fixed in 10.0.0-rc.2.25502.107
  • 9.0.0 up to 9.0.10: fixed in 9.0.10
  • 8.0.0 up to 8.0.21: fixed in 8.0.21
—
Microsoft.AspNetCore.App.Runtime.win-arm10.0.0-rc.1.25451.107
  • 10.0.0-rc.1.25451.107 up to 10.0.0-rc.2.25502.107: fixed in 10.0.0-rc.2.25502.107
  • 9.0.0 up to 9.0.10: fixed in 9.0.10
  • 8.0.0 up to 8.0.21: fixed in 8.0.21
—
Microsoft.AspNetCore.App.Runtime.win-arm648.0.0 ... 8.0.8 (20 versions)
  • 10.0.0-rc.1.25451.107 up to 10.0.0-rc.2.25502.107: fixed in 10.0.0-rc.2.25502.107
  • 9.0.0 up to 9.0.10: fixed in 9.0.10
  • 8.0.0 up to 8.0.21: fixed in 8.0.21
—
Microsoft.AspNetCore.App.Runtime.win-x648.0.0 ... 8.0.8 (20 versions)
  • 10.0.0-rc.1.25451.107 up to 10.0.0-rc.2.25502.107: fixed in 10.0.0-rc.2.25502.107
  • 9.0.0 up to 9.0.10: fixed in 9.0.10
  • 8.0.0 up to 8.0.21: fixed in 8.0.21
—
Microsoft.AspNetCore.App.Runtime.win-x868.0.0 ... 8.0.8 (20 versions)
  • 10.0.0-rc.1.25451.107 up to 10.0.0-rc.2.25502.107: fixed in 10.0.0-rc.2.25502.107
  • 9.0.0 up to 9.0.10: fixed in 9.0.10
  • 8.0.0 up to 8.0.21: fixed in 8.0.21
—
Microsoft.AspNetCore.Server.Kestrel.Core0.0.1-alpha ... 2.3.0 (22 versions)
  • every version up to 2.3.6: fixed in 2.3.6
—

Weakness Classification(1)

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

Additional Vendor Advisories

(10)

Data Freshness Timeline

(refreshed 20× in last 7d / 65× 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 96 of 187 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. 4 repeat rows among the latest 100 are merged into the row they repeat. The 91 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-29 22:29 UTCEG score recompute
  2. 2026-10-29 22:29 UTCVendor advisory
  3. 2026-10-28 22:53 UTCEG score recompute
  4. 2026-10-28 22:53 UTCVendor advisory
  5. 2026-10-28 16:30 UTCEPSS rescoreEPSS 67% · 99th percentile
  6. 2026-10-27 23:18 UTCEG score recompute
  7. 2026-10-27 23:18 UTCVendor advisory
  8. 2026-10-27 16:30 UTCEPSS rescoreEPSS 67% · 99th percentile
  9. 2026-10-26 23:41 UTCEG score recompute
  10. 2026-10-26 23:41 UTCVendor advisory
  11. 2026-10-26 16:30 UTCEPSS rescoreEPSS 67% · 99th percentile
  12. 2026-10-25 20:29 UTCEG score recompute
  13. 2026-10-25 20:29 UTCVendor advisory
  14. 2026-10-25 16:31 UTCEPSS rescoreEPSS 67% · 99th percentile
  15. 2026-10-25 16:17 UTCEG score recompute
  16. 2026-10-24 20:52 UTCEG score recompute
  17. 2026-10-24 20:52 UTCVendor advisory
  18. 2026-10-24 16:31 UTCEPSS rescoreEPSS 67% · 99th percentile
  19. 2026-10-23 21:16 UTCEG score recompute
  20. 2026-10-23 21:16 UTCVendor advisory
  21. 2026-10-22 21:38 UTCEG score recompute
  22. 2026-10-22 21:38 UTCVendor advisory
  23. 2026-10-22 16:33 UTCEPSS rescoreEPSS 67% · 99th percentile
  24. 2026-10-21 22:01 UTCEG score recompute
  25. 2026-10-21 22:01 UTCVendor advisory
Show 71 more
  1. 2026-10-21 16:31 UTCEPSS rescoreEPSS 67% · 99th percentile
  2. 2026-10-20 22:25 UTCEG score recompute
  3. 2026-10-20 22:25 UTCVendor advisory
  4. 2026-10-20 16:31 UTCEPSS rescoreEPSS 67% · 99th percentile
  5. 2026-10-19 22:43 UTCEG score recompute
  6. 2026-10-19 22:43 UTCVendor advisory
  7. 2026-10-19 16:31 UTCEPSS rescoreEPSS 67% · 99th percentile
  8. 2026-10-18 21:30 UTCVendor advisory
  9. 2026-10-18 16:40 UTCEG score recompute
  10. 2026-10-18 16:40 UTCVendor advisory
  11. 2026-10-18 05:25 UTCEG score recompute
  12. 2026-10-17 19:41 UTCEG score recompute
  13. 2026-10-17 19:41 UTCVendor advisory
  14. 2026-10-17 16:33 UTCEPSS rescoreEPSS 66% · 99th percentile
  15. 2026-10-16 20:02 UTCEG score recompute
  16. 2026-10-16 20:02 UTCVendor advisory
  17. 2026-10-16 16:39 UTCEPSS rescoreEPSS 66% · 99th percentile
  18. 2026-10-15 17:35 UTCEG score recompute
  19. 2026-10-15 17:35 UTCVendor advisory
  20. 2026-10-14 16:31 UTCEPSS rescoreEPSS 66% · 99th percentile
  21. 2026-10-14 11:24 UTCEG score recompute
  22. 2026-10-14 11:24 UTCVendor advisory
  23. 2026-10-13 16:33 UTCEPSS rescoreEPSS 66% · 99th percentile
  24. 2026-10-13 10:21 UTCVendor advisory
  25. 2026-10-12 16:56 UTCEG score recompute
  26. 2026-10-12 16:33 UTCEPSS rescoreEPSS 66% · 99th percentile
  27. 2026-10-12 10:44 UTCVendor advisory
  28. 2026-10-11 20:30 UTCEG score recompute
  29. 2026-10-11 18:41 UTCEG score recompute
  30. 2026-10-11 15:17 UTCEG score recompute
  31. 2026-10-10 19:59 UTCEPSS rescoreEPSS 66% · 99th percentile
  32. 2026-10-09 20:06 UTCEPSS rescoreEPSS 66% · 99th percentile
  33. 2026-10-08 17:10 UTCEPSS rescoreEPSS 66% · 99th percentile
  34. 2026-10-07 23:47 UTCEPSS rescoreEPSS 66% · 99th percentile
  35. 2026-10-06 15:17 UTCEPSS rescoreEPSS 66% · 99th percentile
  36. 2026-10-04 23:21 UTCEPSS rescoreEPSS 66% · 99th percentile
  37. 2026-10-03 14:24 UTCEPSS rescoreEPSS 66% · 99th percentile
  38. 2026-10-02 03:10 UTCOSV refresh
  39. 2026-10-01 19:49 UTCEPSS rescoreEPSS 66% · 99th percentile
  40. 2026-09-30 15:02 UTCEPSS rescoreEPSS 66% · 99th percentile
  41. 2026-09-26 15:58 UTCEPSS rescoreEPSS 66% · 99th percentile
  42. 2026-09-24 14:02 UTCEPSS rescoreEPSS 66% · 99th percentile
  43. 2026-09-23 13:47 UTCEPSS rescoreEPSS 66% · 99th percentile
  44. 2026-09-21 21:06 UTCEPSS rescoreEPSS 66% · 99th percentile
  45. 2026-09-20 20:15 UTCEPSS rescoreEPSS 66% · 99th percentile
  46. 2026-09-19 15:42 UTCEPSS rescoreEPSS 66% · 99th percentile
  47. 2026-09-18 19:27 UTCEPSS rescoreEPSS 66% · 99th percentile
  48. 2026-09-17 19:29 UTCEPSS rescoreEPSS 66% · 99th percentile
  49. 2026-09-16 14:07 UTCEPSS rescoreEPSS 66% · 99th percentile
  50. 2026-09-16 05:14 UTCEPSS rescoreEPSS 66% · 99th percentile
  51. 2026-09-13 16:46 UTCEPSS rescoreEPSS 66% · 99th percentile
  52. 2026-09-12 20:36 UTCOSV refresh
  53. 2026-09-12 15:00 UTCEPSS rescoreEPSS 66% · 99th percentile
  54. 2026-09-11 14:52 UTCEPSS rescoreEPSS 66% · 99th percentile
  55. 2026-09-11 09:36 UTCEPSS rescoreEPSS 66% · 99th percentile
  56. 2026-09-10 09:34 UTCEPSS rescoreEPSS 66% · 99th percentile
  57. 2026-09-07 16:00 UTCEPSS rescoreEPSS 66% · 99th percentile
  58. 2026-09-06 13:47 UTCEPSS rescoreEPSS 66% · 99th percentile
  59. 2026-09-05 15:28 UTCEPSS rescoreEPSS 66% · 99th percentile
  60. 2026-09-04 05:06 UTCEPSS rescoreEPSS 66% · 99th percentile
  61. 2026-09-02 14:11 UTCEPSS rescoreEPSS 66% · 99th percentile
  62. 2026-08-30 19:16 UTCEPSS rescoreEPSS 66% · 99th percentile
  63. 2026-08-30 01:21 UTCEPSS rescoreEPSS 66% · 99th percentile
  64. 2026-08-28 21:40 UTCEPSS rescoreEPSS 66% · 99th percentile
  65. 2026-08-26 14:45 UTCEPSS rescoreEPSS 66% · 99th percentile
  66. 2026-08-25 13:48 UTCEPSS rescoreEPSS 66% · 99th percentile
  67. 2026-08-25 01:56 UTCOSV refresh
  68. 2026-08-24 14:16 UTCEPSS rescoreEPSS 66% · 99th percentile
  69. 2026-08-24 09:22 UTCEPSS rescoreEPSS 66% · 99th percentile
  70. 2026-08-21 23:48 UTCEPSS rescoreEPSS 66% · 99th percentile
  71. 2026-08-20 22:54 UTCEPSS rescoreEPSS 66% · 99th percentile

Publicly available exploits

(6 references)

Public exploit code is referenced for this CVE (1 Exploit-DB entry, 3 GitHub PoCs), as are 2 GitHub checker repositories. A GitHub repository named or described as a checker or scanner checks whether a system is affected; it is not necessarily exploit code. Defenders should treat patch urgency accordingly.

  • Exploit-DBEDB-52492
    Published Apr 6, 2026

    ASP.net 8.0.10 - Bypass

    Open source ↗
  • GitHub PoCZemarKhos/CVE-2025-55315-PoC-Exploit
    Published Nov 11, 2025

    CVE-2025-55315 PoC Exploit

    Open source ↗
  • GitHub checkerjlinebau/CVE-2025-55315-Scanner-Monitor
    Published Oct 24, 2025

    Quick and Simple Scripts to Scan for Vulnerable Servers and Packet Level Monitors

    Open source ↗
  • GitHub PoC7huukdlnkjkjba/CVE-2025-55315-
    Published Oct 19, 2025

    专业级HTTP请求走私漏洞利用与自动化渗透测试工具

    Open source ↗
  • GitHub checkernickcopi/CVE-2025-55315-detection-playground
    Published Oct 16, 2025

    Playground to experiment with different behavior on patched/unpatched Kestrel for the CVE-2025-55315 HTTP smuggling vulnerability

    Open source ↗
  • GitHub PoCsirredbeard/CVE-2025-55315-repro
    Published Oct 16, 2025

    Tool that reproduces CVE-2025-55315 in ASP.NET Core.

    Open source ↗

Frequently asked(5)

What is CVE-2025-55315?
CVE-2025-55315 is a critical-severity vulnerability; its CVE record was published on October 14, 2025. Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows an authorized attacker to bypass a security feature over a network.
When was CVE-2025-55315 made public?
CVE-2025-55315 was made public on October 14, 2025: that is the date its CVE record's CNA, Microsoft Corporation, gives for when the vulnerability was made public. The CVE record itself was published on October 14, 2025. EchelonGraph's copy of the record carries a last-modified date of October 18, 2026; the record at its source may have been updated since.
Is CVE-2025-55315 actively exploited?
CVE-2025-55315 is not currently on CISA's Known Exploited Vulnerabilities catalog. EchelonGraph's EG-KEV model places it in Tier 2 (Weaponized), which is not evidence of exploitation: CISA's SSVC data says a public PoC exists and its EPSS is 50% or more. EchelonGraph does not test whether exploit code works. FIRST EPSS estimates a 67% probability of exploitation in the next 30 days (99th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2025-55315?
CVE-2025-55315 has a CVSS v3 base score of 9.9 (NVD).
How do I remediate CVE-2025-55315?
A fix for CVE-2025-55315 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2025-55315 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2025-55315

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