7.5

CVE-2026-59725: Socket.IO: Engine.IO Polling Transport Connection Exhaustion

Analyzed
AliasesRHSA-2026:42986CGA-86x7-wm86-p9f4CGA-x9cw-r5jm-wcrc
Published 08-07-2026Last modified 14-10-2026

Vulnerability summary

CVE-2026-59725 is a high (CVSS 7.5) Improper Resource Shutdown or Release vulnerability in socket engine.io. EPSS estimates a 0.64% chance of exploitation in the next 30 days, higher than 50.5% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.64%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
RHSA-2026:37577CGA-8CWP-XX4P-5GM7

Timeline

  1. 08-07-2026
    PublishedVulnerability first disclosed.
  2. 14-10-2026
    Last modifiedVulnerability information updated.

Description

Socket.IO enables bidirectional and low-latency communication for every platform. From 4.1.0 before 6.6.7, Engine.IO protocol v4 polling transport does not properly close the HTTP response for invalid binary POST requests with Content-Type: application/octet-stream, allowing an unauthenticated attacker to exhaust server-side connections and sockets. This issue is fixed in version 6.6.7.

CVSS metrics

6 scores · 6 sources · 1 version

EPSS trend

Probability

0.64%

Chance of exploitation in the next 30 days

Percentile

51%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.64% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Redhat5 products
  • dotnet-sdk-8.0< 0:8.0.129-2.hum1
  • dotnet-sdk-8.0-source-built-artifacts< 0:8.0.129-2.hum1
  • dotnet-sdk-dbg-8.0< 0:8.0.129-2.hum1
  • dotnet-templates-8.0< 0:8.0.129-2.hum1
  • dotnet8.0< 0:8.0.129-2.hum1
Chainguard3 products
  • jupyter-base-notebook< 7.6.3-r2
  • redisinsight< 3.8.0-r1
  • tensorflow-gpu-jupyterAll versions (No fix recorded)
Npm1 product
  • engine.io≥ 4.1.0, < 6.6.7
Socket1 product
Socketio1 product
Wolfi1 product
  • jupyter-base-notebook< 7.6.3-r2

6 vendors · 12 products

References

13 links
Show all 13 references