CVE-2026-59151: Prowler: SAML Domain Claiming Enables Cross-Tenant Account Takeover

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 0.5%, percentile 44: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 44% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.
• Only applies if your dependency tree includes prowler-cloud (PyPI) < 5.30.3, fixed in 5.30.3. Check your lockfile, including transitive dependencies.

What it is

Prowler is a cloud security platform. Prior to 5.30.3, Prowler's SAML authentication flow trusted the email domain asserted in a SAMLResponse when deciding which tenant should receive the final token, and the ACS finish logic in api/src/backend/api/v1/views.py recalculated the tenant from user.email instead of binding token issuance to the validated SAML configuration. An authenticated attacker with a controlled SAML IdP could complete a valid SAML flow for an attacker-controlled domain while asserting an email address from another configured domain, causing a SAMLToken and tenant-scoped JWT to be issued for the wrong tenant and enabling cross-tenant account takeover. This issue is fixed in version 5.30.3.

From the GitHub advisory

SAML Tenant Binding Enables Cross-Tenant Account Takeover

Summary

Prowler's SAML authentication flow trusted the email domain asserted in a SAMLResponse when deciding which tenant should receive the final token. A malicious tenant with its own SAML configuration and a self-controlled IdP could complete a valid SAML flow for its own configured domain, while asserting an email address from another configured domain.

In the vulnerable flow, the ACS finish logic later derived the tenant from the asserted email domain instead of binding token issuance to the tenant associated with the validated SAML configuration. This could cause a token to be issued for the wrong tenant.

The attacker does not generally need to claim the victim's email domain. If the victim tenant already has SAML configured for that domain, another tenant cannot claim it because SAMLConfiguration.emaildomain and SAMLDomainIndex.emaildomain are globally unique.

Weakness type: CWE-287.

Product: prowler-cloud (PyPI) · Assigned by: GitHub_M · Published: 2026-07-10

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: low (any account)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable no, technical impact partial.
• FIRST EPSS (model of 2026-10-21): 0.53% probability of exploitation activity in the next 30 days; percentile 44.

Timeline

• 2026-07-10 — CVE record published by GitHub_M
• 2026-07-13 — CVE record last updated
• 2026-09-11 — GitHub-reviewed advisory GHSA-h8m9-jgf8-vwvp published (critical)

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-h8m9-jgf8-vwvp github.com
2. CVE.org record CVE-2026-59151 cve.org
3. NVD entry CVE-2026-59151 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com
5. github.com github.com
6. github.com github.com

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