CVE-2026-115927

MEDIUM CVSS 5.3
Published: 2026-10-26
Modified: 2026-10-27
Enriched via mock
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AI Threat Summary

CVE-2026-115927 is a moderate vulnerability with a CVSS score of 5.3 affecting the target software. Authentication can be bypassed allowing unauthenticated access. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.

Description

Tornado is a Python web framework and asynchronous networking library. Prior to 6.6.0, Tornado decodes HTTP/1.1 chunked transfer encoding by processing body data that has already arrived without yielding to the event loop. A remote unauthenticated peer can send millions of one-byte chunks to monopolize the process event loop and stall every other connection served by that process, while lowering max_body_size only limits the duration of each request. For handlers that do not use @stream_request_body, retaining each chunk as a separate object can consume roughly twenty times the received body size, and SimpleAsyncHTTPClient has the same event-loop behavior when reading a response from a malicious server. This issue is fixed in version 6.6.0.

Attack Chain
1
Reconnaissance

Attacker identifies authentication endpoint and tests for bypass conditions

2
Initial Access

Attacker exploits CVE-2026-115927 authentication flaw to gain unauthorized access without valid credentials

3
Discovery

Attacker enumerates accessible resources, users, and configurations

4
Collection

Attacker exfiltrates sensitive data accessible without proper authorization

MITRE ATT&CK Techniques
T1078 Valid Accounts
Initial Access

Authentication bypass grants attacker access as legitimate user

T1548 Abuse Elevation Control Mechanism
Privilege Escalation

Bypassed auth may grant elevated or admin-level permissions

Indicators of Compromise
Type Value Description
user_agent Mozilla/5.0 (compatible; exploit/1.0) Generic exploit scanner user agent pattern
url /api/vuln-endpoint?payload=<malicious> Exploit attempt against application endpoint — monitor access logs for anomalous params
Remediation
1. Apply vendor-supplied security patches immediately. 2. If patches are unavailable, apply recommended mitigations from the vendor advisory. 3. Enable WAF rules or IDS signatures to detect exploitation attempts. 4. Monitor logs for indicators of compromise listed above. 5. Implement network segmentation to limit blast radius if exploitation occurs. 6. Subscribe to vendor security advisories for this product.
Quick Facts
CVE ID CVE-2026-115927
CVSS Score 5.3
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Published 2026-10-26
Exploited No
CISA KEV No
PoC Not public
References
External Resources
NVD Entry BleepingComputer The Hacker News