CVE-2026-59310
CVE-2026-59310 — vCenter directory-traversal vulnerability
VMware vCenter contains a directory traversal vulnerability in the Syslog server. A malicious actor with network access to vCenter may exploit this issue to execute arbitrary code.
Published Updated Sources: NVD, VMware (CNA), CISA, FIRST EPSS, 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 Aug 18, 2026
EPSS
46%
ahead of 99% of scored CVEs
CVSS base
9.8
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.
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 Cloud Foundation 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 Aug 21, 2026 — passed 11 days ago
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 |
|---|---|---|---|
| VMware | Cloud Foundation | 9.1.x.x | Vulnerable |
| VMware | Cloud Foundation | 9.0.x.x | Vulnerable |
| VMware | Cloud Foundation | 5.x | Vulnerable |
| VMware | vSphere Foundation | 9.1.x.x | Vulnerable |
| VMware | vSphere Foundation | 9.0.x.x | Vulnerable |
| VMware | vCenter | 9.1.x.x to < 9.1.0.0300 | Vulnerable |
| VMware | vCenter | 9.0.x.x to < 9.0.2.0100 | Vulnerable |
| VMware | vCenter | 8.0 to < 8.0 U3k | Vulnerable |
| VMware | Telco Cloud Infrastructure | 3.0 | Vulnerable |
| VMware | Telco Cloud Platform | 5.1.x | Vulnerable |
| VMware | Telco Cloud Platform | 5.0.x | Vulnerable |
| VMware | Telco Cloud Platform | 4.x | Vulnerable |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Availability
High
Confidentiality
High
Integrity
High
Scope
Unchanged
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 |
|---|---|---|---|---|---|
| 9.8 | CVSS 3.1 | critical | 3.9 | 5.9 | vmware.com (CNA), VMware (CNA) |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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.
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
- Execute Unauthorized Code or Commands
- Modify Files or Directories
- Read Files or Directories
- DoS: Crash, Exit, or Restart
Mitigation: Assume all input is malicious. Use an accept known good input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, boat may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as red or blue. Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. When validating filenames, use stringent allowlists that limit the character set to be used. If feasible, only allow a single . character in the filename to avoid weaknesses such as CWE-23, and exclude directory separators such as / to avoid CWE-36. Use a list of allowable file extensions, which will help to avoid CWE-434. Do not rely exclusively on a filtering mechanism that removes potentially dangerous characters. This is equivalent to a denylist, which may be incomplete (CWE-184). For example, filtering / is insufficient protection if the filesystem also supports the use of as a directory separator. Another possible error could occur when the filtering is applied in a way that still produces dangerous data (CWE-182). For example, if ../ sequences are removed from the .../...// string in a sequential fashion, two instances of ../ would be removed from the original string, but the remaining characters would still form the ../ string.
Weakness & attack patterns
- CWE-22Path Traversal
Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.
CISA KEV details
CISA lists a CVE here once it has evidence of exploitation against real targets.
Listed
Aug 18, 2026
Federal deadline
Aug 21, 2026
passed 11 days ago
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
Exploit entries
1
Exploit-DB and CTI exploit indexes
Social mentions
Posts naming this CVE. Attention, not evidence of exploitation — it spikes on disclosure and decays whether or not anything is exploited.
2. VMware vCenter, CVE-2026-59310. Unauthenticated RCE, and there is no workaround. Patch is the only control. Vendor patched end of July. Exploitation observed about five days later. Most of the victim population appeared within four days of that.
@tokonkwor· Aug 28, 2026
This week’s What to Watch, Patch, and Secure roundup covers vulnerability exploitation, social engineering, AI security, and supply-chain threats. 🔹 VMware vCenter exploitation Attackers exploited CVE-2026-59310 to compromise VMware vCenter environments, establishing https://t.co/eMlflWRU66
@thehexnode· Aug 28, 2026
Five days from patch to active exploitation. 47 countries. Our team traced CVE-2026-59310 to two lines in vCenter's rsyslog config. The syslog service builds ESX log file paths using the hostname from the incoming message and never escapes it. That's enough to write a file into
@vali_cyber· Aug 27, 2026
RT @quirso_de: New QUIRSO research 🧹 Our investigation into CVE-2026-59310 exploitation in VMware vCenter by a suspected Chinese-nexus APT…
@skocherhan· Aug 26, 2026
🚨 CRITICAL: CVE-2026-59310 - Broadcom VMware vCenter path traversal vulnerability enables remote code execution. Network-accessible attackers can execute arbitrary code. CISA KEV listed. Patch immediately. #CVE #PatchNow #ThreatIntel https://t.co/XUYyBNYCbB
@DFIR_Lab· Aug 26, 2026
35 more posts on this CVEShowing 5 of 40 · Who is discussing this CVE, and how loudlyUnlock freeDetection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Prioritize edge telemetry for network-reachable Cloud Foundation, vSphere Foundation, vCenter, Telco Cloud Infrastructure, Telco Cloud Platform.
- Monitor for scanner or exploit-pattern traffic after 3 public PoC repositories were reported.
Groups associated with this CVE
Groups reported in connection with this vulnerability. A reported association, not a confirmed observation of that group using it — and not scoped to any sector or campaign.
- ip5.34.176.10028
AlienVault OTX Feeds · Aug 17, 2026
- ip146.59.252.17880
AbuseIPDB Hourly Update · May 6, 2026
- hostnameintel.se9ly9upbhay.shop49
AlienVault OTX Feeds · Aug 17, 2026
- ip5.34.177.3828
AlienVault OTX Feeds · Aug 17, 2026
- ip185.144.28.12028
AlienVault OTX Feeds · Aug 17, 2026
1 more indicators on this CVEShowing 5 of 6 · Hashes, addresses and domains from a live threat exchangeUnlock freeTimeline
What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.
- 2026
Added · CVSS 3.1 9.8 (AV:N)
Aug 19, 2026 · NVD
Added to CISA KEV catalog
Aug 18, 2026 · CISA
Cve is exploited BiuTrap/CVE-2026-59310
Aug 17, 2026 · SOCRadar CTI
Initial · CVE published
Jul 30, 2026 · NVD
Source activity
Readings a source repeats on a schedule, counted rather than listed.
- 15×TweetsAug 14, 2026 – Aug 29, 2026 · SOCRadar CTI
- 13×SVRS was changedAug 13, 2026 – Aug 29, 2026 · SOCRadar CTI
- 4×TelegramAug 14, 2026 – Aug 25, 2026 · SOCRadar CTI
- 4×ModifiedAug 14, 2026 – Aug 18, 2026 · SOCRadar CTI
- 2×Github ReposAug 17, 2026 · SOCRadar CTI
References
7 on the record
- support.broadcom.com/web/ecx/support-content-notification/-/external/content/SecurityAdvisories/0/38017
Vendor Advisory, NIST
- medium.com/@quirso_de/active-exploitation-of-cve-2026-59310-361-victim-ips-across-47-countries-9783187cc6ff
Third Party Advisory
- medium.com/@quirso_de/global-exploitation-of-cve-2026-59310-by-suspected-chinese-nexus-apt-related-cve-2026-59309-443a79e1466d
Third Party Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-59310
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-2026-59310
Vendor Advisory
Coverage
20 stories from the feeds we poll
IT Security Weekend Catch Up – August 28, 2026
badcyber.com · Aug 28, 2026
Iran-Linked Hackers Shut UK Power Plant for 4 Days [2026] - tech-insider.org
tech-insider.org · Aug 27, 2026
How to Protect Against Ransomware: 13 Steps, 100 Min [2026] - tech-insider.org
tech-insider.org · Aug 25, 2026
VMware vCenter Zero-Day: CVE-2026-59310 Hits 47 Nations - tech-insider.org
tech-insider.org · Aug 25, 2026
Weekly Cyber Security Newsletter Bulletin – Entra ID RCE, Claude Code Ransomware, T-Mobile Cable, Azure... - CyberSecurityNews
cybersecuritynews.com · Aug 23, 2026
15 more reports on this CVEShowing 5 of 20 · Vendor research and security press coverageUnlock freeElsewhere on this site
- VMwareevery CVE for this vendor
- August 2026what else CISA listed
- Path Traversalsame class
- CWE-22other 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.
- Only the 5 indicator(s) reported for this CVE are available; no packet-level or host-forensic 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-2026-59310 is vCenter directory-traversal vulnerability, a critical vulnerability affecting Cloud Foundation, vSphere Foundation, vCenter, Telco Cloud Infrastructure, Telco Cloud Platform from VMware. The current evidence lists it in CISA KEV, and the exploit status is: Yes: CISA KEV signal present. Public exploit evidence is: 3 public PoC repositories reported; 0 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 9.8 describes technical severity, while EPSS 46% 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.