CVE-2022-25304: All versions of package opcua; all versions of package asyncua are vulnerable to Denial of Service (DoS) due t

This month

HIGH 7.5REMOTEMITIGATEMITIGATE

CVE-2022-25304 is a high-severity flaw (CVSS 7.5) affecting asyncua, opcua. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

All versions of package opcua; all versions of package asyncua are vulnerable to Denial of Service (DoS) due to a missing limitation on the number of received chunks - per single session or in total for all concurrent sessions. An attacker can exploit this vulnerability by sending an unlimited number of huge chunks (e.g. 2GB each) without sending the Final closing chunk.

Why this priority

High severity
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.6% (top 25%)
CISA exploited list	No
Weakness	CWE-770
Published	2022-08-23
Last modified	2026-06-17

Publisher (CNA): Snyk · Vendor: asyncua project · opcua project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2022-08-23 05:15 UTCPublished CVE record published
2026-06-17 04:33 UTCUpdated Record last modified

asyncua project asyncua MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

pip show asyncua

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

opcua project opcua MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

pip show opcua

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2022-25304?

asyncua: mitigate or apply the listed mitigation; opcua: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2022-25304 being exploited?

CVE-2022-25304 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2022-25304 affect?

CVE-2022-25304 affects asyncua, opcua. Severity is high (CVSS 7.5). All versions of package opcua; all versions of package asyncua are vulnerable to Denial of Service (DoS) due to a missing limitation on the number of received chunks - per single session or in total for all concurrent sessions. An attacker

How urgent is CVE-2022-25304?

Priority 50/100. High severity; Remotely exploitable, no login, no user action

References

← Back to latest CVEs