Medium SSRF exploit reference

CVE-2026-40516 — OpenHarness SSRF via web_fetch and web_search

OpenHarness before commit bd4df81 contains a server-side request forgery vulnerability in the web_fetch and web_search tools that allows attackers to access private and localhost HTTP services by manipulating tool parameters without proper validation of target addresses. Attackers can influence an agent session to invoke these tools against loopback, RFC1918, link-local, or other non-public addresses to read response bodies from local development services, cloud metadata endpoints, admin panels, or other private HTTP services reachable from the victim host.

Published Apr 17, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulnCheck

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.3% (30-day exploitation probability)+3
Technical severity (medium)+3
CISA SSVC: exploitation "poc"+5
Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

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

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.29%

ahead of 20% of scored CVEs · Oct 14, 2026

Affects

Hkuds

Openharness

CVSS base

6.3

Medium · 3 source(s)

Prioritization reference: 8.3 provisional

CISA SSVC assessment CISA

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

Exploitation

Proof of concept

none · proof-of-concept · active

Automatable

Yes

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — github.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Hkuds Openharness).
Apply the fixed version or the patch documented under Remediation.
Exploitation requires user interaction: tighten email/web filtering and warn affected users.
Search available logs for exploit probes matching the vulnerability class (ssrf), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Hkuds	Openharness	< 2026-04-11	Vulnerable	NIST National Vulnerability Database
Hkuds	Openharness	< bd4df81f634f8c7cddcc3fdf7f561a13dcbf03ae	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

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

Attack vector

Local

Attack complexity

Low

Privileges required

None

User interaction

Required

Scope

Changed

Confidentiality

High

Integrity

None

Availability

None

Every base score collected

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

Score	Version	Severity	Expl.	Impact	Scored by
7.8	CVSS 4.0	High	—	—	disclosure@vulncheck.com via NIST National Vulnerability Database
7.8	CVSS 4.0	High	—	—	VulnCheck via CVE Program (cve.org) e CISA ADP
8.3	CVSS 3.1	High	3.9	3.7	disclosure@vulncheck.com via NIST National Vulnerability Database
8.3	CVSS 3.1	High	—	—	VulnCheck via CVE Program (cve.org) e CISA ADP
6.3	CVSS 3.1	Medium	1.8	4.0	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N (score shown at the top: nvd@nist.gov)

Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 8.3 (disclosure@vulncheck.com via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-918 · Server-Side Request Forgery (SSRF)

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.29%

Detection

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

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Monitor outbound requests from the server to internal IPs and cloud metadata endpoints.

endpoint telemetry (EDR)egress traffic

Timeline

What happened to this CVE, newest first.

2026
Affected products added · hkuds/openharness
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 6.3
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Apr 17, 2026 · VulnCheck

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

3 on the record

github.com/HKUDS/OpenHarness/commit/bd4df81f634f8c7cddcc3fdf7f561a13dcbf03ae
Patch, patch, NIST National Vulnerability Database
github.com/HKUDS/OpenHarness/pull/92
Exploit, Issue Tracking, issue-tracking, NIST National Vulnerability Database
www.vulncheck.com/advisories/openharness-ssrf-via-web-fetch-and-web-search
Third Party Advisory, third-party-advisory, NIST National Vulnerability Database

Elsewhere on this site

Hkuds
every CVE for this vendor

SSRF
same class

CWE-918
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-56696 OpenHarness - Prompt Injection via /issue and /pr_comments Slash Commands Jun 23, 2026
Medium CVE-2026-56695 OpenHarness - Cross-Session Disclosure via /resume and /summary Commands Jun 23, 2026
High CVE-2026-7551 HKUDS OpenHarness Remote Command Execution via /bridge Slash Command Apr 30, 2026
High CVE-2026-6823 HKUDS OpenHarness Insecure Default Remote Channel Allowlist Apr 21, 2026
High CVE-2026-6819 HKUDS OpenHarness Plugin Management Command Exposure Apr 21, 2026
High CVE-2026-6729 HKUDS OpenHarness Session Key Collision Privilege Escalation Apr 20, 2026

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 record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-40516 is "OpenHarness SSRF via web_fetch and web_search", rated Medium. It affects Openharness (Hkuds); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.3 describes technical severity. EPSS 0.29% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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