Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:LCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-29870 is a high-severity Path Traversal (CWE-22) vulnerability. Its CVSS base score is 7.6 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 45th 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-3 (Access 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-2026-29870 is a directory traversal vulnerability (CWE-22) affecting the agentic-context-engine project in versions up to 0.7.1. The issue resides in the checkpoint_dir parameter passed to OfflineACE.run, where the save_to_file method in ace/skillbook.py does not properly normalize or validate filesystem paths. This flaw enables attackers to use traversal sequences to escape the intended checkpoint directory and perform arbitrary file writes on files accessible to the application process.
The vulnerability has a CVSS v3.1 base score of 7.6 (AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L), indicating it is exploitable over the network with low complexity and requires only low privileges, without user interaction. An authenticated attacker with low privileges can leverage this to overwrite arbitrary files, potentially causing application corruption, privilege escalation, or code execution based on the deployment environment and permissions of the process.
For mitigation details, refer to the security advisory at https://github.com/lilmingwa13/security-research/blob/main/CVE-2026-29870.md, published on 2026-03-31.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-17419
Vulnerability Data
A directory traversal vulnerability in the agentic-context-engine project versions up to 0.7.1 allows arbitrary file writes via the checkpoint_dir parameter in OfflineACE.run. The save_to_file method in ace/skillbook.py fails to normalize or validate filesystem paths, allowing traversal sequences to escape the…
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intended checkpoint directory. This vulnerability allows attackers to overwrite arbitrary files accessible to the application process, potentially leading to application corruption, privilege escalation, or code execution depending on the deployment context.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.3.2
Mitigating Controls (NIST 800-53 r5) AI
Enforces the intended directory access authorizations that path traversal would otherwise bypass.
Input validation directly neutralizes special path elements before pathname construction occurs.
Least privilege reduces the impact of any unauthorized file access obtained via traversal.
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.
Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.
PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.
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 catches path traversal via static/dynamic analysis.
Secure SDLC mandates input validation and path sanitization that directly prevent path traversal.
Application security requirements include rules for safe file handling and canonicalization.
Secure architecture principles require least-privilege file access and directory isolation.
Secure coding standards explicitly forbid unsafe path construction and mandate safe APIs.
Information access restriction limits which files an application may read or write.