How severe is CVE-2019-8259?

CVE-2019-8259 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2019-8259 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-8259?

CVE-2019-8259 primarily affects Uvnc Ultravnc. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2019-8259?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2019-8259 published?

CVE-2019-8259 was published on 2019-03-05 and last updated on 2026-06-17.

CVE-2019-8259

CVE-2019-8259 is a high-severity vulnerability in Uvnc Ultravnc with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-401.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 3% (86th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-401
Affected product: Uvnc Ultravnc
Published: 2019-03-05
Last modified: 2026-06-17

Description

UltraVNC revision 1198 contains multiple memory leaks (CWE-655) in VNC client code, which allow an attacker to read stack memory and can be abused for information disclosure. Combined with another vulnerability, it can be used to leak stack memory and bypass ASLR. This attack appears to be exploitable via network connectivity. These vulnerabilities have been fixed in revision 1199.

Frequently asked questions

What is CVE-2019-8259?: UltraVNC revision 1198 contains multiple memory leaks (CWE-655) in VNC client code, which allow an attacker to read stack memory and can be abused for information disclosure. Combined with another vulnerability, it can be used to leak stack memory and bypass ASLR. This attack appears to be exploitable via network connectivity. These vulnerabilities have been fixed in revision 1199.
How severe is CVE-2019-8259?: CVE-2019-8259 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2019-8259 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-8259?: CVE-2019-8259 primarily affects Uvnc Ultravnc. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-8259?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2019-8259 published?: CVE-2019-8259 was published on 2019-03-05 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:uvnc:ultravnc:*:*:*:*:*:*:*:*
cpe:2.3:a:siemens:sinumerik_access_mymachine\/p2p:*:*:*:*:*:*:*:*
cpe:2.3:a:siemens:sinumerik_pcu_base_win10_software\/ipc:*:*:*:*:*:*:*:*
cpe:2.3:a:siemens:sinumerik_pcu_base_win7_software\/ipc:*:*:*:*:*:*:*:*

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