How severe is CVE-2026-56339?

CVE-2026-56339 has a CVSS 3.x base score of 7.5, 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-2026-56339 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-56339?

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.

When was CVE-2026-56339 published?

CVE-2026-56339 was published on 2026-07-15.

CVE-2026-56339

CVE-2026-56339 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. 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-203.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.7
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-203
Published: 2026-07-15
Last modified: 2026-07-15

Description

Capgo (Cap-go/capgo) before 12.128.2 contains an information disclosure vulnerability in the Supabase PostgREST SECURITY DEFINER RPC function public.rescind_invitation that allows unauthenticated attackers to enumerate organization existence. The function returns distinct error messages (NO_ORG vs NO_RIGHTS) when called with only a publishable API key, enabling attackers to discover valid organization IDs and increase the attack surface for targeted phishing or social engineering campaigns.

Frequently asked questions

What is CVE-2026-56339?: Capgo (Cap-go/capgo) before 12.128.2 contains an information disclosure vulnerability in the Supabase PostgREST SECURITY DEFINER RPC function public.rescind_invitation that allows unauthenticated attackers to enumerate organization existence. The function returns distinct error messages (NO_ORG vs NO_RIGHTS) when called with only a publishable API key, enabling attackers to discover valid organization IDs and increase the attack surface for targeted phishing or social engineering campaigns.
How severe is CVE-2026-56339?: CVE-2026-56339 has a CVSS 3.x base score of 7.5, 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-2026-56339 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-56339?: 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.
When was CVE-2026-56339 published?: CVE-2026-56339 was published on 2026-07-15.

References

Other CWE-203 (Observable Discrepancy) vulnerabilities

CVE-2019-25337 — Critical (CVSS 9.8): OwnCloud 8.1.8 contains a username enumeration vulnerability that allows remote attackers to discover user accounts by…
CVE-2026-23519 — Critical (CVSS 9.8): RustCrypto CMOV provides conditional move CPU intrinsics which are guaranteed on major platforms to execute in…
CVE-2025-39702 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: Fix MAC comparison to be…
CVE-2025-27667 — Critical (CVSS 9.8): Vasion Print (formerly PrinterLogic) before Virtual Appliance Host 22.0.843 Application 20.0.1923 allows Administrative…
CVE-2024-25714 — Critical (CVSS 9.8): In Rhonabwy through 1.1.13, HMAC signature verification uses a strcmp function that is vulnerable to side-channel…
CVE-2024-25191 — Critical (CVSS 9.8): php-jwt 1.0.0 uses strcmp (which is not constant time) to verify authentication, which makes it easier to bypass…

Browse all CWE-203 (Observable Discrepancy) vulnerabilities →