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.
CVE-2026-48804
“—” 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: 0.5% (41st percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2026-56894 (ENISA EUVD) · GHSA-5w7q-77mv-v69f (GitHub Security Advisories)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5HIGHmedium confidence
- EG Risk
- 49EG 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.Exploitation0.5% × 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
- 0.5%
- EPSS %ILE
- 41st
- 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
- 0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). 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: 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.
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 26, 2026
Last Modified
September 10, 2026
Advisory Details (2)
Auto-updated Aug 11, 2026commit 4bec3ef87bcf (miguelgrinberg/python-socketio)
Patch available: miguelgrinberg/python-socketio v5.16.4 (contains commit 4bec3ef87bcf)
https://github.com/miguelgrinberg/python-socketio/commit/4bec3ef87bcfd6ab5b94cd3ac09d873283a6960eBinary attachment accumulation can cause denial of service · Advisory · miguelgrinberg/python-socketio · GitHub
https://github.com/miguelgrinberg/python-socketio/security/advisories/GHSA-5w7q-77mv-v69fVendor 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
(7 across 4 ecosystems)
Debian:12(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python-engineio | 4.11.1-0.1 ... 4.9.0-2 (10 versions) |
| — |
| python-socketio | 5.11.2-1 ... 5.7.2-2 (7 versions) |
| — |
Debian:13(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python-engineio | 4.11.2-1, 4.12.1-1, 4.12.1-2, 4.13.0-1, 4.13.0-2 |
| — |
| python-socketio | 5.12.1-1, 5.13.0-1, 5.16.0-1, 5.17.0-1 |
| — |
Debian:14(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python-engineio | 4.11.2-1, 4.12.1-1, 4.12.1-2, 4.13.0-1, 4.13.0-2 |
| — |
| python-socketio | 5.12.1-1, 5.13.0-1, 5.16.0-1 |
| — |
PyPI(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python-socketio | 0.1.0 ... 5.9.0 (107 versions) |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 37× 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.
- 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-25 14:23 UTCEG score recompute
- 2026-10-24 22:53 UTCEG score recompute
- 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-18 03:34 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-17 12:14 UTCEG score recompute
- 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-13 20:54 UTCOSV refresh
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-12 16:00 UTCEG score recompute
- 2026-10-11 19:43 UTCEG score recompute
- 2026-10-11 16:58 UTCEG score recompute
- 2026-10-11 14:22 UTCEG score recompute
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- 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-26 00:27 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-09-23 07:48 UTCEG score recompute
- 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-09-18 07:11 UTCEG score recompute
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-09-14 01:00 UTCEG score recompute
- 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-09-12 15:33 UTCEG score recompute
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-09-10 20:39 UTCEG score recompute
- 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-09-06 15:01 UTCEG score recompute
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-08-30 19:20 UTCEG score recompute
- 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-08-27 23:00 UTCEG score recompute
- 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-08-24 21:47 UTCEG score recompute
- 2026-08-23 07:53 UTCEG score recompute
- 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-08-22 09:24 UTCEG score recompute
- 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-08-21 04:55 UTCEG score recompute
- 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-08-20 06:44 UTCEG score recompute
- 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-08-18 23:42 UTCEG score recompute
- 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-08-16 20:00 UTCEG score recompute
- 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-08-16 08:44 UTCEG score recompute
- 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-08-15 10:59 UTCEG score recompute
- 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-08-14 02:21 UTCEG score recompute
- 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-08-13 15:28 UTCEG score recompute
- 2026-08-13 15:17 UTCEG score recompute
- 2026-08-12 18:06 UTCEG score recompute
- 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-08-11 20:21 UTCEG score recompute
- 2026-07-30 11:09 UTCEG score recompute
- 2026-07-26 14:31 UTCEG score recompute
- 2026-07-23 03:18 UTCEG score recompute
- 2026-06-26 21:40 UTCEG score recompute
Related CVEs(same product + same CWE)
Same product
4 shownDebian:12:python-socketio · Debian:12:python-engineio
Frequently asked(5)
What is CVE-2026-48804?
When was the CVE record for CVE-2026-48804 published?
Is CVE-2026-48804 actively exploited?
What is the CVSS score of CVE-2026-48804?
How do I remediate CVE-2026-48804?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-48804
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