NVD / CVE Program· CNA mitre

CVE-2019-12855: In words.protocols.jabber.xmlstream in Twisted through 19.2.1, XMPP support did not verify certificates when used with TLS, allowing an atta

Noroxi assessment

Priority: Monitor (action score 30/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 1.8% (FIRST EPSS); higher than 78.4% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
Fixed version: twisted (Debian:12) 18.9.0-7; python-Twisted (openSUSE:Leap 15.0) 17.9.0-lp151.3.6.1; python-Twisted (openSUSE:Tumbleweed) 21.7.0-3.2.

Low priority for now. Upgrade to twisted (Debian:12) 18.9.0-7; python-Twisted (openSUSE:Leap 15.0) 17.9.0-lp151.3.6.1; python-Twisted (openSUSE:Tumbleweed) 21.7.0-3.2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.4 · v3.0—No exploit Fix available

Published: Jun 16, 2019
Updated: Jun 16, 2026
EPSS: 1.8% · 78th percentile
CWE: CWE-295

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 29 / 40 · 7.4 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 1 / 30 · 1.8%

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Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
twisted	twisted	cpe:2.3:a:twisted:twisted

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This vulnerability is about certificate validation or weak cryptography. The free SSL checker tests your certificate, enabled TLS versions and weak ciphers.

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Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

twisted twistedup to 19.2.1 inclusive

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	twisted	before 18.9.0-7	18.9.0-7
openSUSE:Leap 15.0	python-Twisted	before 17.9.0-lp151.3.6.1	17.9.0-lp151.3.6.1
openSUSE:Tumbleweed	python-Twisted	before 21.7.0-3.2	21.7.0-3.2
PyPI	twisted	before 19.7.0rc1	19.7.0rc1
SUSE:HPE Helion OpenStack 8	python-Twisted	before 15.2.1-9.8.1	15.2.1-9.8.1
SUSE:Package Hub 15	python-Twisted	before 17.9.0-bp150.4.6.1	17.9.0-bp150.4.6.1

Same product

twisted: all records

Other highest-scoring records for the same primary product.

CVE-2020-10109In Twisted Web through 19.10.0, there was an HTTP request splitting vulnerability.
40Plan
CVE-2020-10108In Twisted Web through 19.10.0, there was an HTTP request splitting vulnerability.
40Plan
CVE-2026-115775Twisted: Unauthenticated Remote Denial of Service in the Twisted words domish XML Element Stream via an Unbounded Element Tree
34Monitor

Published before and after this one in the same product

← EarlierCVE-2019-12387Jun 10, 2019 · In Twisted before 19.2.1, twisted.web did not validate or sanitize URIs or HTTP methods, allowing an attacker to inject invalid characters s
25Monitor
Later →CVE-2014-7143Nov 12, 2019 · Python Twisted 14.0 trustRoot is not respected in HTTP client
31Monitor
Later →CVE-2016-1000111Mar 11, 2020 · Twisted before 16.3.1 does not attempt to address RFC 3875 section 4.1.18 namespace conflicts and therefore does not protect CGI application
22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
debian:twisted	18.9.0-7 · Debian:12	Package registry (OSV)
opensuse:python-Twisted	17.9.0-lp151.3.6.1 · openSUSE:Leap 15.0	Package registry (OSV)
PyPI:twisted	19.7.0rc1	Package registry (OSV)
suse:python-Twisted	15.2.1-9.8.1 · SUSE:HPE Helion OpenStack 8	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

twisted/twistedPR 1147

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
Special conditions such as timing or configuration are required.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: none

Attack vector: Network
Attack complexity: High
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: None

Weakness class (CWE)

CWE-295 · Improper Certificate Validation

CVSS vector

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

nvd-primary

Root cause

A certificate validation error is silently swallowed instead of terminating the connection. Often, code added for a test environment makes its way into production.

The bug in code

The whole CWE-295 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

kotlin

1override fun checkServerTrusted(chain: Array<X509Certificate>, type: String) {
2  // Left empty for the test environment
3}

Fixed

kotlin

1val client = OkHttpClient.Builder()
2  .certificatePinner(
3    CertificatePinner.Builder()
4      .add("api.sirius.example", "sha256/…")
5      .build()
6  ).build()

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log

Fix✗ → ✓Sep 28, 2026, 10:44 PM UTC

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References

lists.opensuse.org/opensuse-security-announce/2019-09/msg00013.html

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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