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Full vulnerability report · 2019
CVE-2019-5010High confidence

An exploitable denial-of-service vulnerability exists in the X509 certificate parser of Python.org Python 2.7.11 / 3.6.6

Unknown · Python

Official source article: Red Hat RHSA-2019:3520 ↗. Check the applicable product and release in the original source.

7.5HighCVSS 3.1
Recommended action
Within 7 days

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Critical, raised one band.upgradedsince 4 Aug 2024

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 20.74% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Unknown Python and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Alpine findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

6 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Alpine v3.23v3.23 · mainpython3Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.3.6.8-r1Alpine Security Database ↗Source updated 23 Oct 2026
Alpine v3.23v3.23 · mainpython3-tkinterVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.3.6.8-r1Alpine Security Database ↗Source updated 23 Oct 2026
Alpine v3.22v3.22 · communitypython3-tkinterVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.3.6.8-r1Alpine Security Database ↗Source updated 22 Oct 2026
Alpine v3.22v3.22 · mainpython3Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.3.6.8-r1Alpine Security Database ↗Source updated 23 Oct 2026
Alpine v3.21v3.21 · communitypython3-tkinterVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.3.6.8-r1Alpine Security Database ↗Source updated 22 Oct 2026
Alpine v3.21v3.21 · mainpython3Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.3.6.8-r1Alpine Security Database ↗Source updated 23 Oct 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2019-5010 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitypython: NULL pointer dereference using a specially crafted X509 certificate
8 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • rh-python35-python as a component of Red Hat Software Collections
  • rh-python35-python-debug as a component of Red Hat Software Collections
  • rh-python35-python-devel as a component of Red Hat Software Collections
  • rh-python35-python-libs as a component of Red Hat Software Collections
  • rh-python35-python-test as a component of Red Hat Software Collections
  • rh-python35-python-tkinter as a component of Red Hat Software Collections
  • rh-python35-python-tools as a component of Red Hat Software Collections
  • rh-python35-python.src as a component of Red Hat Software Collections
Summary
A null pointer dereference vulnerability was found in the certificate parsing code in Python. This causes a denial of service to applications when parsing specially crafted certificates. This vulnerability is unlikely to be triggered if application enables SSL/TLS certificate validation and accepts certificates only from trusted root certificate authorities.
Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2019-14617

No EUVD known-exploited evidence

An exploitable denial-of-service vulnerability exists in the X509 certificate parser of Python.org Python 2.7.11 / 3.6.6. A specially crafted X509 certificate can cause a NULL pointer dereference, resulting in a denial of service. An attacker can initiate or accept TLS connections using crafted certificates to trigger this vulnerability.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
5.9 · CVSS 3.0
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

An exploitable denial-of-service vulnerability exists in the X509 certificate parser of Python.org Python 2.7.11 / 3.6.6. A specially crafted X509 certificate can cause a NULL pointer dereference, resulting in a denial of service. An attacker can initiate or accept TLS connections using crafted certificates to trigger this vulnerability.

What

An exploitable denial-of-service vulnerability exists in the X509 certificate parser of Python.org Python 2.7.11 / 3.6.6. A specially crafted X509 certificate can cause a NULL pointer dereference, resulting in a denial of service. An attacker can initiate or accept TLS connections using crafted certificates to trigger this vulnerability.

Why

The product dereferences a pointer that it expects to be valid but is NULL.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

An exploitable denial-of-service vulnerability exists in the X509 certificate parser of Python.org Python 2.7.11 / 3.6.6. A specially crafted X509 certificate can cause a NULL pointer dereference, resulting in a denial of service. An attacker can initiate or accept TLS connections using crafted certificates to trigger this vulnerability.

Why

The product dereferences a pointer that it expects to be valid but is NULL.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
a network path → NULL Pointer Dereference → disrupt the affected service
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-476 ↗

CWE-476: NULL Pointer Dereference. The product dereferences a pointer that it expects to be valid but is NULL.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedDenial of serviceCWE-476Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2019-14617Official EUVD mapping

An exploitable denial-of-service vulnerability exists in the X509 certificate parser of Python.org Python 2.7.11 / 3.6.6. A specially crafted X509 certificate can cause a NULL pointer dereference, resulting in a denial of service. An attacker can initiate or accept TLS connections using crafted certificates to trigger this vulnerability.

Official EUVD record ↗
BSI · German · WID-SEC-2024-1601Python: Mehrere Schwachstellen ermöglichen Denial of Service

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Python ausnutzen, um einen Denial of Service Angriff durchzuführen.

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-267Multiples vulnérabilités dans Juniper Networks Junos Space

CVERecord?id=CVE-2019-20386 Référence CVE CVE-2019-20485 https://www.cve.org/CVERecord?id=CVE-2019-20485 Référence CVE CVE-2019-20636 https://www.cve.org/CVERecord?id=CVE-2019-20636 Référence CVE CVE-2019-20811 https://www.cve.org/CVERecord?id=CVE-2019-20811 Référence CVE CVE-2019-20907 https://www.cve.org/CVERecord?id=CVE-2019-20907 Référence CVE CVE-2019-3820 https://www.cve.org/CVERecord?id=CVE-2019-3820 Référence CVE CVE-2019-3840 https://www.cve.org/CVERecord?id=CVE-2019-3840 Référence CVE CVE-2019-3890 https://www.cve.org/CVERecord?id=CVE-2019-3890 Référence CVE CVE-2019-3901 https://www.cve.org/CVERecord?id=CVE-2019-3901 Référence CVE CVE-2019-5010 https://www.cve.org/CVERecord?id=CVE-2019-5010 Référence CVE CVE-2019-5094 https://www.cve.org/CVERecord?id=CVE-2019-5094 Référence CVE CVE-2019-5188 https://www.cve.org/CVERecord?id=CVE-2019-5188 Référence CVE CVE-2019-5953 https://www.cve.org/CVERecord?id=CVE-2019-5953 Référence CVE CVE-2019-6133 https://www.cve.org/CVERecord?id=CVE-2019-6133 Référence CVE CVE-2019-6690 https://www.cve.org/CVERecord?id=CVE-2019-6690 Référence CVE CVE-2019-6778 https://www.cve.org/CVERecord?id=CVE-2019-6778 Référence CVE CVE-2019-7149 https://www.cve.org/CVERecord?id=CVE-2019-7149 Référence CVE CVE-2019-7150 https://www.cve.org/CVERecord?id=CVE-2019-7150 Ré

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2019-011524Python.org Python における NULL ポインタデリファレンスに関する脆弱性

Python.org Python には、NULL ポインタデリファレンスに関する脆弱性が存在します。

Official advisory ↗
NCSC-NL · Dutch · NCSC-2025-0041Kwetsbaarheden verholpen in F5 BIG-IP

Een kwaadwillende kan de kwetsbaarheden misbruiken om aanvallen uit te voeren die kunnen leiden tot de volgende categorieën schade: - Denial-of-Service (DoS) - Omzeilen van een beveiligingsmaatregel - Uitvoer van willekeurige code (Root/admin) - Uitvoer van willekeurige code (Gebruiker) - Toegang tot gevoelige gegevens

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
Action
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 31 Oct 2019 · Last source change 7 Oct 2026, 18:55 UTC · CWE-476 · NULL Pointer Dereference

CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-09-01
European sourceENISA EUVD · EUVD-2019-14617
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD modified after enrichment

Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    Python: Python.org CPython 2.7.11 Python.org CPython 3.6.6 Python.org CPython 3.5.2 Python.org CPython 3 master at 480833808e918a1dcebbbcfd07d5a8de3c5c2a66 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    Python: Python.org CPython 2.7.11 Python.org CPython 3.6.6 Python.org CPython 3.5.2 Python.org CPython 3 master at 480833808e918a1dcebbbcfd07d5a8de3c5c2a66 · Fixed: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
    Red Hat Product Security ↗
  2. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    Red Hat Product Security ↗
  3. Affected versionsThe structured affected or fixed version information changed.
    Before
    Python.org CPython 2.7.11 Python.org CPython 3.6.6 Python.org CPython 3.5.2 Python.org CPython 3 master at 480833808e918a1dcebbbcfd07d5a8de3c5c2a66 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    Python: Python.org CPython 2.7.11 Python.org CPython 3.6.6 Python.org CPython 3.5.2 Python.org CPython 3 master at 480833808e918a1dcebbbcfd07d5a8de3c5c2a66 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CNA ↗
  4. ENISA EUVD mappingEUVD-2019-14617 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2019-14617"}
    ENISA EUVD ↗
  5. Vendor guidanceAuthoritative vendor guidance changed: removed vendor advisory: access.redhat.com/RHSA-2019:3520; removed vendor advisory: access.redhat.com/RHSA-2019:3725; 2 further removals.
    Before
    vendor advisory: access.redhat.com/RHSA-2019:3520 · vendor advisory: access.redhat.com/RHSA-2019:3725 · vendor advisory: lists.opensuse.org/msg00040.html · 1 more references
    After
    no authoritative guidance recorded
    CNA ↗
  6. Public exploit evidencePublic exploit evidence changed from No public exploit to Public exploit reference.
    Before
    No public exploit
    After
    Public exploit reference
    talosintelligence.com ↗
  7. SeveritySeverity changed from Medium to High.
    Before
    Medium
    After
    High
    NIST NVD ↗
  8. CVSS scoreCVSS score changed from 5.9 (CVSS 3.0 · CNA · CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H) to 7.5 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
    Before
    5.9 (CVSS 3.0 · CNA · CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H)
    After
    7.5 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
    NIST NVD ↗
  9. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2019-14617↗Red Hat Product Security security advisory↗CVE authority or vendor reference · Red Hat RHSA-2019:3520↗Public exploit reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2019-5010 · cve.blacktree.nl