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Full vulnerability report · 2026
CVE-2026-7774High confidence

tarfile.data_filter path traversal bypass allows writing outside the extraction directory

Python Software Foundation · CPython

6.9MediumCVSS 4.0
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Mitigation available
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

2 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.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archivepypy3Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivepython3.12Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.3.12.3-1ubuntu0.15Canonical record ↗Source updated 8 Sept 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-2026-7774 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitypython: CPython: Python tarfile: Arbitrary file write via crafted link entries
134 known affected

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

  • exploit-intelligence-tech-preview/vulnerability-analysis-rhel9 as a component of Exploit Intelligence
  • python-unversioned-command as a component of Red Hat Enterprise Linux 10
  • python3 as a component of Red Hat Enterprise Linux 10
  • python3-debug as a component of Red Hat Enterprise Linux 10
  • python3-devel as a component of Red Hat Enterprise Linux 10
  • python3-idle as a component of Red Hat Enterprise Linux 10
  • python3-libs as a component of Red Hat Enterprise Linux 10
  • python3-test as a component of Red Hat Enterprise Linux 10
  • python3-tkinter as a component of Red Hat Enterprise Linux 10
  • python3.12.src as a component of Red Hat Enterprise Linux 10
  • python as a component of Red Hat Enterprise Linux 6
  • python-devel as a component of Red Hat Enterprise Linux 6
Summary
A flaw was found in the `tarfile.data_filter` function within the Python `tarfile` module. A remote attacker could exploit this vulnerability by providing a specially crafted tar archive containing malicious link entries, such as symlinks with empty or directory-like names. This bypass allows the attacker to redirect subsequent archive members outside the intended extraction directory, leading to arbitrary file writes on the system where the archive is extracted. The impact of this flaw is limited by the permissions of the extracting process.
Remediation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Optional official sources

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

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

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-2026-34282

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

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
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Mitigation available
01

What, why and how

tarfile.data_filter could be bypassed using crafted link entries, including symlinks with empty or directory-like names, to redirect later archive members outside the intended extraction directory. This allowed a malicious tar archive to cause tarfile.extractall() to write files outside the destination directory, subject to the permissions of the extracting process.

What

tarfile.data_filter could be bypassed using crafted link entries, including symlinks with empty or directory-like names, to redirect later archive members outside the intended extraction directory. This allowed a malicious tar archive to cause tarfile.extractall() to write files outside the destination directory, subject to the permissions of the extracting process.

Why

Attacker-controlled path data is not constrained to the intended directory before the application accesses a file.

How

An attacker operating through a network path may attempt exploitation when the stated preconditions are met. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

tarfile.data_filter could be bypassed using crafted link entries, including symlinks with empty or directory-like names, to redirect later archive members outside the intended extraction directory. This allowed a malicious tar archive to cause tarfile.extractall() to write files outside the destination directory, subject to the permissions of the extracting process.

Why

Attacker-controlled path data is not constrained to the intended directory before the application accesses a file.

How

An attacker operating through a network path may attempt exploitation when the stated preconditions are met. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

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.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
Active interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-22 ↗

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'). The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Common Vulnerability Scoring System 4.0: 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.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIActiveUser interaction: A user must take a deliberate action for exploitation to succeed.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
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.
NetworkUnauthenticatedCWE-22
A

Official authority intelligence

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

BSI · German · WID-SEC-W-2026-1796CPython: Schwachstelle ermöglicht Manipulation von Dateien

Ein entfernter, anonymer Angreifer kann eine Schwachstelle in CPython ausnutzen, um Dateien zu manipulieren.

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0753Multiples vulnérabilités dans Microsoft Azure

De multiples vulnérabilités ont été découvertes dans Microsoft Azure. Elles permettent à un attaquant de provoquer un problème de sécurité non spécifié par l'éditeur.

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0691Multiples vulnérabilités dans CPython

De multiples vulnérabilités ont été découvertes dans CPython. Certaines d'entre elles permettent à un attaquant de provoquer une atteinte à l'intégrité des données, un contournement de la politique de sécurité et un déni de service.

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.
Mitigation available
Affected
exploit-intelligence-tech-preview/vulnerability-analysis-rhel9 as a component of Exploit Intelligence; python-unversioned-command as a component of Red Hat Enterprise Linux 10; python3 as a component of Red Hat Enterprise Linux 10; python3-debug as a component of Red Hat Enterprise Linux 10; python3-devel as a component of Red Hat Enterprise Linux 10; python3-idle as a component of Red Hat Enterprise Linux 10; python3-libs as a component of Red Hat Enterprise Linux 10; python3-test as a component of Red Hat Enterprise Linux 10; python3-tkinter as a component of Red Hat Enterprise Linux 10; python3.12.src as a component of Red Hat Enterprise Linux 10; python as a component of Red Hat Enterprise Linux 6; python-devel as a component of Red Hat Enterprise Linux 6; python-libs as a component of Red Hat Enterprise Linux 6; python-test as a component of Red Hat Enterprise Linux 6; python-tools as a component of Red Hat Enterprise Linux 6; python.src as a component of Red Hat Enterprise Linux 6; tkinter as a component of Red Hat Enterprise Linux 6; python as a component of Red Hat Enterprise Linux 7; python-debug as a component of Red Hat Enterprise Linux 7; python-devel as a component of Red Hat Enterprise Linux 7; python-libs as a component of Red Hat Enterprise Linux 7; python-test as a component of Red Hat Enterprise Linux 7; python-tools as a component of Red Hat Enterprise Linux 7; python.src as a component of Red Hat Enterprise Linux 7; python3 as a component of Red Hat Enterprise Linux 7; python3-debug as a component of Red Hat Enterprise Linux 7; python3-devel as a component of Red Hat Enterprise Linux 7; python3-idle as a component of Red Hat Enterprise Linux 7; python3-libs as a component of Red Hat Enterprise Linux 7; python3-test as a component of Red Hat Enterprise Linux 7; and 104 more
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
04

Evidence and provenance

Published 4 Jun 2026 · Last source change 13 Aug 2026, 00:26 UTC · CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-34282
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD awaiting enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2026-34282↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor 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-2026-7774 · cve.blacktree.nl