CVE-2026-48804

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 80% of all CVEs by exploit prediction. 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: epss, secondary
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

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

python-socketio is a Python implementation of the Socket.IO realtime client and server. The python-socketio server stores binary EVENT and ACK messages in memory while it waits to receive their binary attachments. Once all the attachments are received, these messages are then processed. Prior to version 5.16.4, an attacker can submit a binary message and intentionally omit sending one or more of its attachments to cause the message along with the partial list of received attachments to stay in memory for a long time. Version 5.16.4 takes the following measures to address this issue: Binary packets are only accepted from authenticated clients and, when a client disconnects, the server checks if there is a partial binary message being held for the client and deletes it.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
20%
KEV
Not listed

Published

June 26, 2026

Last Modified

September 10, 2026

Advisory Details (2)

Auto-updated Aug 11, 2026
Patch available. Sources: github_commit, github.
github_commit Patch Available

commit 4bec3ef87bcf (miguelgrinberg/python-socketio)

Patch available: miguelgrinberg/python-socketio v5.16.4 (contains commit 4bec3ef87bcf)

https://github.com/miguelgrinberg/python-socketio/commit/4bec3ef87bcfd6ab5b94cd3ac09d873283a6960e
github Patch Available

Binary attachment accumulation can cause denial of service · Advisory · miguelgrinberg/python-socketio · GitHub

https://github.com/miguelgrinberg/python-socketio/security/advisories/GHSA-5w7q-77mv-v69f

Vendor Advisories for CVE-2026-48804(1)

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

Affected Packages

(4 across 4 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
python-engineio4.11.1-0.1 ... 4.9.0-2 (10 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
python-engineio4.11.2-1, 4.12.1-1, 4.12.1-2, 4.13.0-1, 4.13.0-2——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
python-engineio4.11.2-1, 4.12.1-1, 4.12.1-2, 4.13.0-1, 4.13.0-2——
PyPI(1)
PackageVulnerable rangeFixed inDependents
python-socketio0.1.0 ... 5.9.0 (107 versions)5.16.2—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 41× 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. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-10 20:39 UTCEG score recompute
  3. 2026-09-10 09:35 UTCEPSS rescore
  4. 2026-09-08 22:01 UTCEPSS rescore
  5. 2026-09-07 16:01 UTCEPSS rescore
  6. 2026-09-06 15:01 UTCEG score recompute
  7. 2026-09-06 13:47 UTCEPSS rescore
  8. 2026-09-04 05:06 UTCEPSS rescore
  9. 2026-09-02 14:12 UTCEPSS rescore
  10. 2026-09-01 13:54 UTCEPSS rescore
  11. 2026-09-01 04:40 UTCEPSS rescore
  12. 2026-08-30 19:20 UTCEG score recompute
  13. 2026-08-30 19:17 UTCEPSS rescore
  14. 2026-08-30 01:22 UTCEPSS rescore
  15. 2026-08-28 21:41 UTCEPSS rescore
  16. 2026-08-27 23:00 UTCEG score recompute
  17. 2026-08-27 14:25 UTCEPSS rescore
  18. 2026-08-26 14:46 UTCEPSS rescore
  19. 2026-08-25 13:49 UTCEPSS rescore
  20. 2026-08-24 21:47 UTCEG score recompute
  21. 2026-08-23 07:53 UTCEG score recompute
  22. 2026-08-23 00:19 UTCEPSS rescore
  23. 2026-08-22 09:24 UTCEG score recompute
  24. 2026-08-21 23:49 UTCEPSS rescore
  25. 2026-08-21 04:55 UTCEG score recompute
Show 23 more
  1. 2026-08-20 22:55 UTCEPSS rescore
  2. 2026-08-20 06:44 UTCEG score recompute
  3. 2026-08-19 17:04 UTCEPSS rescore
  4. 2026-08-18 23:42 UTCEG score recompute
  5. 2026-08-18 13:48 UTCEPSS rescore
  6. 2026-08-17 13:47 UTCEPSS rescore
  7. 2026-08-16 20:00 UTCEG score recompute
  8. 2026-08-16 14:56 UTCEPSS rescore
  9. 2026-08-16 08:44 UTCEG score recompute
  10. 2026-08-16 02:14 UTCEPSS rescore
  11. 2026-08-15 10:59 UTCEG score recompute
  12. 2026-08-15 01:30 UTCEPSS rescore
  13. 2026-08-14 02:21 UTCEG score recompute
  14. 2026-08-13 22:00 UTCEPSS rescore
  15. 2026-08-13 15:28 UTCEG score recompute
  16. 2026-08-13 15:17 UTCEG score recompute
  17. 2026-08-12 18:06 UTCEG score recompute
  18. 2026-08-12 13:51 UTCEPSS rescore
  19. 2026-08-11 20:21 UTCEG score recompute
  20. 2026-07-30 11:09 UTCEG score recompute
  21. 2026-07-26 14:31 UTCEG score recompute
  22. 2026-07-23 03:18 UTCEG score recompute
  23. 2026-06-26 21:40 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-48804?
CVE-2026-48804 is a high vulnerability published on June 26, 2026. python-socketio is a Python implementation of the Socket.IO realtime client and server. The python-socketio server stores binary EVENT and ACK messages in memory while it waits to receive their binary attachments. Once all the attachments are received, these messages are then processed. Prior to…
When was CVE-2026-48804 disclosed?
CVE-2026-48804 was first published in the National Vulnerability Database on June 26, 2026, with the most recent update on September 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-48804 actively exploited?
CVE-2026-48804 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 79.8% of all scored CVEs.
What is the CVSS score of CVE-2026-48804?
CVE-2026-48804 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-48804?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-48804, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-48804

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