What is CVE-2026-49869?

CVE-2026-49869 is Kestra: Unauthenticated Remote Code Execution via Authentication Bypass in `AuthenticationFilter`. The supplied enrichment data classifies it as Remote Code Exec mapped to CWE-78 OS Command Injection; CWE-184 CWE-184; CWE-287 Improper Authentication; CWE-918 Server-Side Request Forgery (SSRF).

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Yes: CISA KEV signal present. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

Is there a public exploit?

8 public PoC repositories reported; 2 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS, EDR process telemetry, host service logs where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-49869 using CVSS 10, EPSS 1%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Treat as emergency remediation because CISA KEV status is present. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

CISA KEVcriticalRemote Code Execpublic exploit

CVE-2026-49869

CVE-2026-49869 — Kestra: Unauthenticated Remote Code Execution via Authentication Bypass in `AuthenticationFilter`

Q: Is it in CISA KEV?

Yes. The supplied enrichment data lists CVE-2026-49869 in CISA KEV with 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.. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

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.

Published Jun 26, 2026Updated Sep 2, 2026Sources: NVD, kestra-io (CNA), CISA, FIRST EPSS, GitHub, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Confirmed

CISA KEV, listed Sep 2, 2026

EPSS

ahead of 60% of scored CVEs

Affects

kestra-io

2 products listed

CVSS base

critical

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

Active

none · proof-of-concept · active

Automatable

Yes

can an attacker script all four kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Upgrade kestra to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

CISA 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.

Federal deadline Sep 5, 2026 — today

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Treat as emergency remediation because CISA KEV status is present.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
kestra-io	kestra	< 1.0.45	Vulnerable
kestra-io	kestra	>= 1.1.0, < 1.3.21	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

High

Confidentiality

High

Integrity

High

Scope

Changed

Attack Complexity

Low

Attack Vector

Network

Privileges Req

None

User Interaction

None

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
10	CVSS 3.1	critical	3.9	6	GitHub (CNA), kestra-io (CNA)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-184 · Incomplete List of Disallowed Inputs

Bypass Protection Mechanism::

Mitigation: Do not rely exclusively on detecting disallowed inputs. There are too many variants to encode a character, especially when different environments are used, so there is a high likelihood of missing some variants. Only use detection of disallowed inputs as a mechanism for detecting suspicious activity. Ensure that you are using other protection mechanisms that only identify good input - such as lists of allowed inputs - and ensure that you are properly encoding your outputs.::

CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Execute Unauthorized Code or Commands
DoS: Crash, Exit, or Restart
Read Files or Directories
Modify Files or Directories

Mitigation: If at all possible, use library calls rather than external processes to recreate the desired functionality.

Weakness & attack patterns

CWE-78OS Command Injection
CWE-184
CWE-287Improper Authentication
CWE-918Server-Side Request Forgery (SSRF)

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-15 · Command DelimitersCAPEC-88 · OS Command InjectionCAPEC-43 · Exploiting Multiple Input Interpretation LayersCAPEC-108 · Command Line Execution through SQL InjectionCAPEC-6 · Argument Injection

T1548Abuse Elevation Control Mechanism
T1040Network Sniffing
T1185Browser Session Hijacking

CISA KEV details

CISA lists a CVE here once it has evidence of exploitation against real targets.

CISAThat month →

Listed

Sep 2, 2026

Federal deadline

Sep 5, 2026

today

Ransomware use

Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a date to argue against.

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

2 of the 5 sampled are weaponized

Social mentions

Posts naming this CVE. Attention, not evidence of exploitation — it spikes on disclosure and decays whether or not anything is exploited.

4 more posts on this CVEShowing 5 of 9 · Who is discussing this CVE, and how loudlyUnlock free

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Search application, proxy, and WAF logs for requests touching /configs.
Prioritize edge telemetry for network-reachable kestra.
Monitor for scanner or exploit-pattern traffic after 8 public PoC repositories were reported.

web/proxy/WAF logsapplication logsnetwork IDS/IPSEDR process telemetryhost service logs

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added to CISA KEV catalog
Sep 2, 2026 · CISA
Added · CVSS 3.1 10.0 (AV:N)
Sep 2, 2026 · NVD
Initial · CVE published
Jun 26, 2026 · NVD

Source activity

Readings a source repeats on a schedule, counted rather than listed.

6×SvrsJun 27, 2026 – Aug 17, 2026 · SOCRadar CTI
6×TweetsJun 27, 2026 – Jul 22, 2026 · SOCRadar CTI
1×Github_Repos · Github repository created, Ap0dexMe0/CVE-2026-49869Jun 30, 2026 · SOCRadar CTI
1×CVE appeared in the Cve Trends.Jun 27, 2026 · SOCRadar CTI
1×CVE modified by MITRE: CVSS metrics updated.Jun 26, 2026 · SOCRadar CTI

References

5 on the record

github.com/kestra-io/kestra/security/advisories/GHSA-5vc5-wxxq-3fjx
Exploit, Vendor Advisory, Mitre, NIST, GITHUB
www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-49869
US Government Resource, NIST
www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
US Government Resource
www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
US Government Resource
nvd.nist.gov/vuln/detail/CVE-2026-49869
Vendor Advisory

Coverage

5 stories from the feeds we poll

Elsewhere on this site

kestra-ioevery CVE for this vendor
September 2026what else CISA listed
Remote Code Execsame class
CWE-78other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2026-49869 is Kestra: Unauthenticated Remote Code Execution via Authentication Bypass in `AuthenticationFilter`, a critical vulnerability affecting kestra from kestra-io. The current evidence lists it in CISA KEV, and the exploit status is: Yes: CISA KEV signal present. Public exploit evidence is: 8 public PoC repositories reported; 2 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 10 describes technical severity, while EPSS 1% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.