How severe is CVE-2026-28508?

CVE-2026-28508 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-28508 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-28508?

CVE-2026-28508 affects Withknown Known. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-28508?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-28508 have an EU (EUVD) identifier?

Yes. CVE-2026-28508 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9984.

When was CVE-2026-28508 published?

CVE-2026-28508 was published on 2026-03-06 and last updated on 2026-06-17.

CVE-2026-28508

CVE-2026-28508 is a high-severity vulnerability in Withknown Known with a CVSS 3.x base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-918.

Key facts

Severity: High (CVSS 3.x base score 8.6)
CVSS v4: 9.2
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-9984
Weakness: CWE-918
Affected product: Withknown Known
Published: 2026-03-06
Last modified: 2026-06-17

Description

Idno is a social publishing platform. Prior to version 1.6.4, a logic error in the API authentication flow causes the CSRF protection on the URL unfurl service endpoint to be trivially bypassed by any unauthenticated remote attacker. Combined with the absence of a login requirement on the endpoint itself, this allows an attacker to force the server to make arbitrary outbound HTTP requests to any host, including internal network addresses and cloud instance metadata services, and retrieve the response content. This issue has been patched in version 1.6.4.

Frequently asked questions

What is CVE-2026-28508?: Idno is a social publishing platform. Prior to version 1.6.4, a logic error in the API authentication flow causes the CSRF protection on the URL unfurl service endpoint to be trivially bypassed by any unauthenticated remote attacker. Combined with the absence of a login requirement on the endpoint itself, this allows an attacker to force the server to make arbitrary outbound HTTP requests to any host, including internal network addresses and cloud instance metadata services, and retrieve the response content. This issue has been patched in version 1.6.4.
How severe is CVE-2026-28508?: CVE-2026-28508 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-28508 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-28508?: CVE-2026-28508 affects Withknown Known. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-28508?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-28508 have an EU (EUVD) identifier?: Yes. CVE-2026-28508 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9984.
When was CVE-2026-28508 published?: CVE-2026-28508 was published on 2026-03-06 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:withknown:known:*:*:*:*:*:*:*:*

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