CVE-2026-48809

HIGHPre-NVD 7.57.5
EchelonGraph scoreLOW confidence

This high-severity CVE scores 7.5 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: cna:github_m
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: —CVSS: 7.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

python-engineio has possible denial of service due to maximum payload size sometimes not being enforced

Impact

There are two specific configurations of the python-engineio server in which the size of incoming messages is not checked before the messages are loaded into memory. An attacker can take advantage of these to cause unnecessary memory allocations in the python-engineio server. The two cases are:
  • POST requests, when using ASGI with the long polling transport
  • WebSocket messages, when using Aiohttp with the WebSocket transport

Patches

Version 4.13.2 addresses this issue as follows:
  • ASGI severs now only load the body of incoming requests into memory after the client is confirmed to be known and authenticated, and the payload size is below the maximum allowed size. Requests that do not comply with these requirements are discarded.
  • Aiohttp servers configure the maximum payload size in the underlying WebSocket layer from Aiohttp, so that large messages are discarded by Aiohttp before they are delivered to python-engineio.

CVSS v3
7.5
EG Score
7.5(low)
EPSS
—
KEV
Not listed

Published

June 26, 2026

Last Modified

June 26, 2026

Vendor Advisories for CVE-2026-48809(1)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 23× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

  1. 2026-07-07 03:20 UTCEG score recompute
  2. 2026-07-06 16:10 UTCEG score recompute
  3. 2026-07-06 05:00 UTCEG score recompute
  4. 2026-07-05 17:51 UTCEG score recompute
  5. 2026-07-05 06:41 UTCEG score recompute
  6. 2026-07-04 19:32 UTCEG score recompute
  7. 2026-07-04 08:21 UTCEG score recompute
  8. 2026-07-03 21:08 UTCEG score recompute
  9. 2026-07-03 10:00 UTCEG score recompute
  10. 2026-07-02 22:50 UTCEG score recompute
  11. 2026-07-02 11:42 UTCEG score recompute
  12. 2026-07-02 00:28 UTCEG score recompute
  13. 2026-07-01 13:17 UTCEG score recompute
  14. 2026-07-01 02:07 UTCEG score recompute
  15. 2026-06-30 14:56 UTCEG score recompute
  16. 2026-06-30 03:47 UTCEG score recompute
  17. 2026-06-29 16:38 UTCEG score recompute
  18. 2026-06-29 05:29 UTCEG score recompute
  19. 2026-06-28 18:20 UTCEG score recompute
  20. 2026-06-28 07:10 UTCEG score recompute
  21. 2026-06-27 20:00 UTCEG score recompute
  22. 2026-06-27 08:50 UTCEG score recompute
  23. 2026-06-26 21:40 UTCEG score recompute

Frequently asked(4)

What is CVE-2026-48809?
CVE-2026-48809 is a high vulnerability published on June 26, 2026. python-engineio has possible denial of service due to maximum payload size sometimes not being enforced Impact There are two specific configurations of the python-engineio server in which the size of incoming messages is not checked before the messages are loaded into memory. An attacker can take…
When was CVE-2026-48809 disclosed?
CVE-2026-48809 was first published in the National Vulnerability Database on June 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-48809?
CVE-2026-48809 has a CVSS v4.0 base score of 7.5 (CNA self-assessment; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-48809?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-48809, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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