Unauthenticated arbitrary file creation/truncation in Splunk Enterprise PostgreSQL Sidecar Service
CVE-2026-20253 is a critical missing-authentication vulnerability in the PostgreSQL Sidecar Service used by Splunk Enterprise. In affected Splunk Enterprise 10.2 releases prior to 10.2.4 and 10.0 releases prior to 10.0.7, the PostgreSQL sidecar recovery endpoint exposed through Splunk Web does not properly enforce authentication, allowing a network-reachable unauthenticated attacker to invoke backup and related file-operation functionality. As documented by Splunk and corroborated by public technical analysis, the vulnerable endpoint can be abused to create or truncate arbitrary files on the underlying system. Public reporting further indicates the file-operation primitive can be chained with attacker-controlled PostgreSQL connection parameters and restore behavior to achieve arbitrary file write and ultimately remote code execution under the Splunk service account. Splunk Enterprise 9.4 and earlier are not affected.
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Impact, mitigation & remediation
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Impact
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Mitigation
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Remediation
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Exploits
1 valid exploit after Mallory filtered fakes, detection scripts, and README-only repos (3 hidden).
Repository is a small standalone Python PoC for CVE-2026-20253 against Splunk Enterprise. It contains one primary code file (splunk_cve_2026_20253.py), dependency metadata (requirements.txt), and several Spanish-language documentation files covering installation, execution examples, detection/mitigation, contribution guidance, and security policy. The exploit script uses requests and disables TLS verification warnings. Its core logic defines a SplunkExploit class with methods to: (1) test unauthenticated access to the Splunk recovery backup endpoint using a POST request with JSON and an empty Basic Authorization header; (2) abuse the backup endpoint to create or truncate arbitrary files by supplying attacker-controlled backupFile paths; and (3) attempt RCE by preparing a Python payload that runs a shell command via /bin/sh -c and writes output to a chosen file. The script references the full attack chain involving PostgreSQL backup/restore primitives and a controlled PostgreSQL server, but the included code is explicitly described as a simplified demonstration that overwrites a Splunk Secure Gateway Python script path to achieve execution. In main(), it supports vulnerability checking, cleanup, arbitrary file creation as a proof step, command execution, and optional retrieval of output from a web-accessible Splunk static directory. Overall, this is a real exploit PoC rather than a detector-only script; however, based on the provided content it appears partially simplified/truncated relative to a full end-to-end weaponized chain, so OPERATIONAL is the best fit.
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Recent activity
177 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
An unauthenticated remote code execution vulnerability in Splunk Enterprise caused by exposure of PostgreSQL sidecar recovery functionality through Splunk Web, enabling proxy access to internal endpoints, arbitrary file creation/write, credential reuse via .pgpass, and eventual code execution.
An improper authentication vulnerability in the PostgreSQL sidecar service of Splunk Enterprise that allows unauthenticated remote attackers to create or truncate arbitrary files on affected systems.
A critical missing-authentication vulnerability in Splunk Enterprise affecting a PostgreSQL sidecar service endpoint, allowing unauthenticated attackers to create or truncate arbitrary files on affected systems.
A critical Splunk Enterprise vulnerability caused by missing authentication controls on a PostgreSQL sidecar service endpoint, allowing unauthenticated arbitrary file creation or truncation and potentially enabling remote code execution.
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