How severe is CVE-2019-6256?

CVE-2019-6256 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2019-6256 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-6256?

CVE-2019-6256 primarily affects Live555 Live555 Media Server. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2019-6256?

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

When was CVE-2019-6256 published?

CVE-2019-6256 was published on 2019-01-14 and last updated on 2026-06-17.

CVE-2019-6256

CVE-2019-6256 is a critical-severity vulnerability in Live555 Live555 Media Server with a CVSS 3.x base score of 9.8. 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-755.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-755
Affected product: Live555 Live555 Media Server
Published: 2019-01-14
Last modified: 2026-06-17

Description

A Denial of Service issue was discovered in the LIVE555 Streaming Media libraries as used in Live555 Media Server 0.93. It can cause an RTSPServer crash in handleHTTPCmd_TunnelingPOST, when RTSP-over-HTTP tunneling is supported, via x-sessioncookie HTTP headers in a GET request and a POST request within the same TCP session. This occurs because of a call to an incorrect virtual function pointer in the readSocket function in GroupsockHelper.cpp.

Frequently asked questions

What is CVE-2019-6256?: A Denial of Service issue was discovered in the LIVE555 Streaming Media libraries as used in Live555 Media Server 0.93. It can cause an RTSPServer crash in handleHTTPCmd_TunnelingPOST, when RTSP-over-HTTP tunneling is supported, via x-sessioncookie HTTP headers in a GET request and a POST request within the same TCP session. This occurs because of a call to an incorrect virtual function pointer in the readSocket function in GroupsockHelper.cpp.
How severe is CVE-2019-6256?: CVE-2019-6256 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2019-6256 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-6256?: CVE-2019-6256 primarily affects Live555 Live555 Media Server. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-6256?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2019-6256 published?: CVE-2019-6256 was published on 2019-01-14 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:live555:live555_media_server:0.93:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

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