Missing Authorization in PostgreSQL Logical Decoding Lets REPLICATION Role Run Code
CVSS 3.1
7.2high
EPSS
<1%p21
Published
()
Modified
AI analysis
CVE-2026-6471 is a missing-authorization flaw (CWE-862) in PostgreSQL's logical decoding that does not restrict which decoding plugin a replication role may load. An attacker holding a database role with the REPLICATION privilege but without superuser rights can select an arbitrary logical decoding plugin, causing the server to dlopen any file visible to the operating-system account running PostgreSQL and thereby execute arbitrary code as that account. Successful exploitation gives code execution as the PostgreSQL service account (typically the 'postgres' OS user) on the database host, with high impact on confidentiality, integrity, and availability; related reporting indicates the flaw has existed for roughly 12 years and is commonly reached through backup or replication accounts. All deployments on PostgreSQL versions prior to 18.6, 17.11, 16.15, 15.19, and 14.24 are affected where non-superusers have been granted the REPLICATION privilege. No exploitation in the wild, public proof-of-concept, or CISA KEV listing is known; EPSS currently estimates a 0.3% probability of exploitation within the next 30 days.
What to do: Upgrade to PostgreSQL 18.6, 17.11, 16.15, 15.19, or 14.24 depending on the branch in use. As interim mitigation, audit all roles holding the REPLICATION privilege, revoke it from users who do not need replication or logical decoding, and restrict which decoding plugins may be selected. Pay particular attention to backup and replication service accounts, which related reporting highlights as the likely abuse path.
Affected
PostgreSQL
All versions before 18.6 (18.x branch)
PostgreSQL
All versions before 17.11 (17.x branch)
PostgreSQL
All versions before 16.15 (16.x branch)
PostgreSQL
All versions before 15.19 (15.x branch)
PostgreSQL
All versions before 14.24 (14.x branch)
Estimated exposure
massmillions of installations (PostgreSQL is deployed across millions of on-prem and managed-cloud database instances, though only hosts granting REPLICATION to… — PostgreSQL is one of the most widely deployed databases worldwide, including very large managed fleets on AWS, Azure, and Google Cloud, and the flawed code has been present for about 12 years across all supported branches, so the total…
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Description
Missing authorization in PostgreSQL logical decoding allows a non-superuser holding REPLICATION privilege to dlopen any file visible to the operating system account running the server, via the choice of logical decoding plugin. This in turn runs arbitrary code as that account. Versions before PostgreSQL 18.6, 17.11, 16.15, 15.19, and 14.24 are affected.
Weekly roundup: Microsoft patches 973 flaws including two actively exploited zero-days; FortiOS CAPWAP flaw deploys PivotC2 RAT; PAN-OS root RCE disclosed.
Microsoft's September 2026 Patch Tuesday fixed 973 vulnerabilities, including two zero-days under active exploitation: CVE-2026-85880 (Windows ALPC) and CVE-2026-81963 (Windows Update Stack), both elevation-of-privilege bugs. SOCRadar reported active exploitation of CVE-2025-25249 (CVSS 9.8) in FortiOS CAPWAP, deploying a Node.js RAT called PivotC2 that exfiltrates Exchange mailboxes to Wasabi cloud storage; 178 devices were compromised out of 30,000 scanned IPs, attributed to a Russian-speaking financially motivated group. Palo Alto disclosed CVE-2026-0310, a 9.2-rated buffer overflow enabling root code execution on PA-Series firewalls, and Fortinet disclosed CVE-2026-84393, a ZTNA certificate validation MITM flaw. Cyera also revealed CVE-2026-6471 ('PostGREShell'), a 12-year-old PostgreSQL logical-decoding flaw allowing code execution via REPLICATION-privileged accounts.
PostgreSQL flaw CVE-2026-6471, present since 2014, lets low-privilege replication accounts execute code and take over database servers; patches released.
Cyera researchers disclosed PostGREShell (CVE-2026-6471, CVSS 7.2), a missing-authorization bug in PostgreSQL logical decoding that lets users with REPLICATION privilege dlopen arbitrary files and execute code as the server account. The flaw affects PostgreSQL 9.4 through 18 and can yield privilege escalation, permanent superuser access and persistent backdoors on Windows, Linux and macOS. Fixes are available in versions 18.6, 17.11, 16.15, 15.19 and 14.24. Defenders should update and remove unnecessary Replication privileges.
Cyera disclosed CVE-2026-6471, a decade-old PostgreSQL flaw letting REPLICATION-attribute accounts achieve RCE and superuser compromise, patched August 13.
Cyera Research's 'PostGREShell' flaw exists in PostgreSQL's logical replication output plugin loading, where the replication code path never called the library-path security check, allowing path traversal or UNC paths to load arbitrary code. A low-privilege backup account can achieve code execution on Windows, Linux, and macOS, then escalate to superuser with persistent backdoor access. CVE-2026-6471 affects versions back to PostgreSQL 9.4 (2014) and was patched in releases 18.6, 17.11, 16.15, 15.19, and 14.24 on August 13. CVSS is 7.2, and no exploitation of this specific CVE has been confirmed, though VirusTotal hunting found 114 malicious PostgreSQL plugins.
PostgreSQL fixed CVE-2026-6471 (CVSS 7.2), a 12-year-old logical decoding flaw letting replication-role accounts execute arbitrary code as the database OS user.
PostgreSQL patched CVE-2026-6471 (CVSS 7.2), a flaw present since logical decoding shipped in 9.4 (2014) that lets an account with the REPLICATION attribute run arbitrary code as the database server's OS user when wal_level is logical. Versions before 18.6, 17.11, 16.15, 15.19, and 14.24 are affected; exploitation requires such an account, which backup, CDC, and monitoring tooling routinely holds. The fix adds an output_plugin_libraries whitelist, so administrators using non-default plugins such as wal2json and decoderbufs must add them and reload configuration after updating. Cyera Research, whose write-up names the flaw PostGREShell, demonstrated escalating a replication user to superuser with persistence; no PoC or KEV entry existed as of September 4.