September 2026 CVE Landscape
Recorded Future says 80 vulnerabilities were actively exploited in September 2026, including NetScaler zero-days.
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CVE-2026-49869
Authentication bypass leading to unauthenticated RCE in Kestra OSS
CISA: Kestra OSS OS Command Injection Vulnerability
- CVSS 3.1
- 10.0 critical
- EPSS
- 2%p82
- Published
- ·
- Added to KEV
AI analysisSummaries by Vani AI
CVE-2026-49869 is a critical (CVSS 3.1: 10.0) authentication bypass in the open-source Kestra event-driven orchestration platform: the AuthenticationFilter exempts the public configuration endpoint from Basic Auth using a suffix match (request paths ending in "/configs") rather than an exact path comparison. As a result, an unauthenticated remote attacker can call any API URL whose final path segment is "configs", which is enough to create and execute arbitrary workflows without credentials. Because Kestra ships with script execution plugins (plugin-script-shell, plugin-script-python, etc.) enabled by default, this directly yields unauthenticated remote code execution as root inside the Kestra worker container. All Kestra OSS deployments prior to 1.0.45 and 1.3.21 are affected, with the greatest risk for instances whose API is reachable from the internet or untrusted networks. The flaw is being actively exploited: CISA added it to the KEV catalog on 2026-09-02 (EPSS 1.9%, percentile 79), and headlines covering the KEV batch report attackers deploying reverse shells and crypto miners.
What to do: Upgrade to Kestra 1.0.45 (for the 1.0.x line) or 1.3.21 (for the 1.3.x line), or later releases that incorporate the fix. If immediate patching is not possible, restrict network access to the Kestra API (firewall/ACL or a reverse proxy that enforces authentication for all paths, including any ending in /configs). Given active exploitation, audit instances for signs of compromise such as unexplained workflows, reverse shells, or cryptomining processes in worker containers; federal agencies must patch per CISA BOD 26-04 timelines.
| Product | Affected |
|---|---|
| Kestra OSS (kestra) | All versions prior to 1.0.45 and prior to 1.3.21; fixed in 1.0.45 and 1.3.21 |
Estimated exposure
moderatelikely low thousands of internet-exposed Kestra instances (estimate; no authoritative install or scan counts in source data) — Kestra is a moderately adopted open-source orchestrator that is typically self-hosted and kept on internal networks, so based on typical deployment patterns only a fraction of its install base is directly internet-exposed, plausibly on the…
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Description · NVD
Kestra is an open-source, event-driven orchestration platform. Prior to 1.0.45 and 1.3.21, AuthenticationFilter in Kestra OSS uses request.getPath().endsWith("/configs") to whitelist the public configuration endpoint from Basic Auth. Because the check is a suffix match rather than an exact path match, any API path whose last segment is configs bypasses authentication entirely. An unauthenticated remote attacker can exploit this to create and execute arbitrary workflows without credentials. Because Kestra ships with script execution plugins (plugin-script-shell, plugin-script-python, etc.) enabled by default, this directly results in unauthenticated Remote Code Execution as root inside the Kestra worker container. This vulnerability is fixed in 1.0.45 and 1.3.21.
KEVCISA Known Exploited Vulnerability
- Affected
- Kestra Kestra OSS
- Required action
- Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
- Due date
- Ransomware use
- Unknown
- Vendors
- kestra
- Products
- kestra
- Weakness
- CWE-78, CWE-184, CWE-287, CWE-918
- Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
In the news
3 storiesCISA Adds Seven Exploited Flaws as Attackers Deploy Reverse Shells and Crypto Miners
CISA added seven actively exploited vulnerabilities to its KEV catalog, including SonicWall SMA 1000 SSRF CVE-2026-83548, amid campaigns deploying reverse shells and crypto miners.
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CISA Adds Seven Known Exploited Vulnerabilities to Catalog
CISA added seven actively exploited vulnerabilities to its KEV catalog, including SonicWall SMA1000 SSRF and command injection flaws.
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