ZeroHour

CVE-2026-73236

niche

Cross-Realm Authorization Bypass in Apache Syncope Delegated Administration

CVSS 3.1
7.5 high
EPSS
Published
()
Modified
AI analysis

Apache Syncope, an open-source identity management platform, enforces delegated administration entitlements by checking whether a target object's Realm sits under an administrator's assigned Realm, using prefix matches on realm names. Due to an incorrect implementation (CWE-863), two sibling Realms whose names begin with the same string cannot be distinguished, so a delegated administrator for one Realm can effectively act on objects in the other Realm. An authenticated attacker holding delegated-administrator rights over one realm gains unauthorized access to users, groups, and other managed objects in the sibling realm — a horizontal privilege escalation between administrative domains. Affected deployments are Apache Syncope 3.0.0-M0 through 3.0.16, 4.0.0-M0 through 4.0.7, and 4.1.0-M0 through 4.1.2; fixes ship in 4.0.8 and 4.1.3, with no patched 3.0.x release listed. No public proof of concept is known, the issue is not in CISA's KEV, and there is no indication of exploitation in the wild.

What to do: Upgrade to Apache Syncope 4.0.8 or 4.1.3 as soon as possible; 3.0.x has no fixed release, so deployments on that line must migrate to a patched 4.x version. Until patched, avoid sibling Realm names that share a leading string and review delegated-administration assignments for realms whose names could collide. Audit Syncope logs for delegated administrators performing operations on realms outside their assigned scope.

Affected
Apache Syncope3.0.0-M0 through 3.0.16
Apache Syncope4.0.0-M0 through 4.0.7
Apache Syncope4.1.0-M0 through 4.1.2
Estimated exposure
nichelikely hundreds to low thousands of self-hosted deployments worldwide (order-of-magnitude estimate) — Apache Syncope is a self-hosted, open-source enterprise IdM platform with no public install telemetry and a small install base relative to commercial IAM suites, so this is an order-of-magnitude guess based on typical deployment patterns…

Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.

Description

Incorrect Authorization vulnerability in Apache Syncope. Delegated administration security checks are based on Realm hierarchy and enforced via prefix matches. Due to incorrect implementation, two sibling Realms whose names begin with the same string cannot be correctly distinguished, resulting in incorrect authorization. This issue affects Apache Syncope: from 3.0.0-M0 through 3.0.16, from 4.0.0-M0 Through 4.0.7, from 4.1.0-M0 through 4.1.2. Users are recommended to upgrade to version 4.0.8 / 4.1.3, which fix this issue.

Weakness
CWE-863
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

In the news

CVE-2026-73236: Apache Syncope: Cross-Realm authorization bypass in delegated administration

Apache Syncope CVE-2026-73236 bypasses delegated administration checks for sibling Realms sharing a name prefix.

Apache Syncope disclosed CVE-2026-73236, an important-rated incorrect authorization vulnerability. Delegated administration checks are enforced via Realm hierarchy prefix matches, so two sibling Realms whose names begin with the same string cannot be correctly distinguished, allowing delegated admins to act outside their assigned Realm. The flaw affects Syncope 3.0.0-M0 through 3.0.16, 4.0.0-M0 through 4.0.7, and 4.1.0-M0 through 4.1.2. Users should upgrade to fixed versions.

oss-security · 1d agoVulnerabilityCVE-2026-732361