Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2026-34515 is a medium-severity Absolute Path Traversal (CWE-36) vulnerability in Aiohttp Aiohttp. Its CVSS base score is 6.6 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 36th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-34515 affects AIOHTTP, an asynchronous HTTP client/server framework for asyncio and Python, specifically versions prior to 3.13.4. On Windows systems, the static resource handler may expose sensitive information about an NTLMv2 remote path. This vulnerability is classified under CWE-36 (Absolute Path Traversal) and CWE-918 (Server-Side Request Forgery), with a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N), indicating high confidentiality impact.
Unauthenticated attackers with network access can exploit this issue with low complexity and no user interaction required. By targeting the static resource handler, they can trigger the disclosure of NTLMv2 remote path details, potentially revealing internal network paths or credentials-related information that could aid further attacks like lateral movement.
The issue has been addressed in AIOHTTP version 3.13.4, as detailed in the project's security advisory (GHSA-p998-jp59-783m), release notes, and the patching commit. Security practitioners should upgrade to version 3.13.4 or later to mitigate the vulnerability.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-18039
Vulnerability Data
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, on Windows the static resource handler may expose information about a NTLMv2 remote path. This issue has been patched in version 3.13.4.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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Mitigating Controls (NIST 800-53 r5) AI
Information flow enforcement can restrict which destinations the server is allowed to contact on behalf of users.
Input validation directly stops construction of absolute paths from untrusted data before they reach file operations.
Enforced access authorizations can limit which resources are reachable even if a traversal succeeds.
Boundary protection limits the network reach of server-initiated requests even if SSRF occurs.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require input validation and path sanitization that prevent absolute path traversal.
Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.
Vulnerability identification processes can discover and record SSRF flaws in web applications.
Network segmentation and egress controls can limit the damage from successful SSRF requests.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect absolute path traversal via static analysis and fuzzing.
Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.
Secure development lifecycle includes input validation and path-handling requirements that reduce absolute path traversal risk.
Application security requirements typically mandate controls against path traversal in file-access functions.
Secure architecture principles call for canonicalization and sandboxing that limit absolute path traversal.
Secure coding standards directly require neutralization of absolute path sequences in pathname construction.