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CVE-2019-12855

24
FAUCET Score

CVE-2019-12855 describes a critical vulnerability in the XMPP support within Twisted through version 19.2.1, where TLS certificates were not properly verified, enabling Man-in-the-Middle (MITM) attacks. This vulnerability carries a high CVSS score of 7.4, indicating a high impact on confidentiality and integrity with a high attack complexity, as an unauthenticated attacker could intercept and manipulate communications. Despite its severity, there is no evidence of active exploitation, publicly available exploit code, or significant community discussion or media coverage surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
<= 19.2.1CPE matchmatch criteria
cpe:2.3:a:twisted:twisted:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.0

7.4HIGH

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
Exploitability Score
2.2
Impact Score
5.2
CvssVersion
3.0

Exploit Intelligence

EPSS Score
1.81%
Probability of exploitation in next 30 days
EPSS Percentile
76.3%
Percentile rank of EPSS score among Peer Group
As of 2026-07-25
Model: v2026.06.15
This CVE's current EPSS score of 0.0181 is in the 34th percentile among its peer group of 8,914 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (16)

github_advisorypatch availablevia nvd_reference
View patch
microsoftpatch availablevia msrc
Product: 17003-16820Fixed in: 20.3.0-1
microsoftpatch availablevia msrc
Product: 17004-16823Fixed in: 22.2.0-1
microsoftpatch availablevia msrc
Product: CBL Mariner 2.0 ARMFixed in: 22.2.0-1
microsoftpatch availablevia msrc
Product: CBL Mariner 2.0 x64Fixed in: 22.2.0-1
microsoftpatch availablevia msrc
Product: CBL Mariner 1.0 ARMFixed in: 20.3.0-1
microsoftpatch availablevia msrc
Product: CBL Mariner 1.0 x64Fixed in: 20.3.0-1
microsoftpatch availablevia msrc
Product: cm1 python-twisted 20.3.0-1 on CBL Mariner 1.0Fixed in: 20.3.0-1
microsoftpatch availablevia msrc
Product: cbl2 python-twisted 22.2.0-1 on CBL Mariner 2.0Fixed in: 22.2.0-1
pippatch availablevia ghsa
Product: twistedFixed in: 19.7.0rc1
redhatend of lifevia redhat_api
Product: Red Hat OpenStack Platform 9 (Mitaka) Operational ToolsFixed in: python-twisted
redhatend of lifevia redhat_api
Product: Red Hat OpenStack Platform 9 (Mitaka)Fixed in: python-twisted
redhatend of lifevia redhat_api
Product: Red Hat OpenStack Platform 13 (Queens)Fixed in: python-twisted
redhatend of lifevia redhat_api
Product: Red Hat OpenStack Platform 10 (Newton)Fixed in: python-twisted
redhatend of lifevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: python-twisted-words
redhatend of lifevia redhat_api
Product: Red Hat Ceph Storage 2Fixed in: calamari-server

Vendor Advisories (4)

microsoft2021-Jul/CVE-2019-12855

CVE-2019-12855

Jul 13, 2021
pipGHSA-65rm-h285-5cc5critical

Improper Certificate Validation in Twisted

Aug 16, 2019
redhatCVE-2019-12855Moderate

python-twisted: XMPP support in words.protocols.jabber.xmlstream in Twisted does not verify certificates allowing for a MITM connections

Jul 9, 2019
microsoft2019-Jun/CVE-2019-12855Important

In words.protocols.jabber.xmlstream in Twisted through 19.2.1 XMPP support did not verify certificates when used with TLS allowing an attacker to MITM connections.

Jun 11, 2019

References

lists.opensuse.org / opensuse-security-announce/2019-09/msg00013.html
lists.opensuse.org / opensuse-security-announce/2019-09/msg00028.html
github.com / twisted/twisted/pull/1147
PatchThird Party Advisory
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/PLTZDMFBNFSJMBXYJNGJHENJA4H2TSMZ
twistedmatrix.com / trac/ticket/9561
Vendor Advisory
usn.ubuntu.com / 4308-1
usn.ubuntu.com / 4308-2
oracle.com / security-alerts/cpuapr2020.html