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Full vulnerability report · 2026
CVE-2026-11972High confidence

tarfile opened in streaming mode mishandles EOF

Python Software Foundation · CPython

8.2HighCVSS 4.0
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Distribution package intelligence

Ubuntu vendor package status

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

1 package state
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 archivepython3.12Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical record ↗Source updated 10 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-2026-11972 · CSAF 2.0 · revision 3 · status not statedRed Hat Product Securitypython: Python tarfile module: Denial of Service via improper EOF handling in streaming mode
101 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
  • rhaii/model-opt-cuda-rhel9 as a component of Red Hat AI Inference Server
  • rhaii/vllm-cpu-rhel9 as a component of Red Hat AI Inference Server
  • rhaii/vllm-cuda-rhel9 as a component of Red Hat AI Inference Server
  • rhaii/vllm-gaudi-rhel9 as a component of Red Hat AI Inference Server
  • rhaii/vllm-neuron-rhel9 as a component of Red Hat AI Inference Server
  • rhaii/vllm-rocm-rhel9 as a component of Red Hat AI Inference Server
  • rhaii/vllm-spyre-rhel9 as a component of Red Hat AI Inference Server
  • rhaii/vllm-tpu-rhel9 as a component of Red Hat AI Inference Server
  • rhaiis/model-opt-cuda-rhel9 as a component of Red Hat AI Inference Server
  • rhaiis/vllm-cpu-rhel9 as a component of Red Hat AI Inference Server
  • rhaiis/vllm-cuda-rhel9 as a component of Red Hat AI Inference Server
Summary
A flaw was found in the Python `tarfile` module. When processing a specially crafted tar archive opened in 'streaming mode' (mode='r|'), the module does not properly handle the end-of-file (EOF) condition. This can cause the `tarfile` module to enter an infinite loop, leading to a Denial of Service (DoS) for applications processing such archives.
Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
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-2026-38630

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 actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

When using the "tarfile" module with a file opened in "streaming mode" (mode="r|") the tarfile module did not properly handle EOF, making archive parsing take exponentially longer.

What

When using the "tarfile" module with a file opened in "streaming mode" (mode="r|") the tarfile module did not properly handle EOF, making archive parsing take exponentially longer.

Why

The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

When using the "tarfile" module with a file opened in "streaming mode" (mode="r|") the tarfile module did not properly handle EOF, making archive parsing take exponentially longer.

Why

The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. 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 → Unchecked Return Value → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
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-252 ↗

CWE-252: Unchecked Return Value. The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.

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:P/PR:N/UI:N/VC:N/VI:N/VA:H/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.ATPresentAttack requirements: A particular deployment or execution condition must be present.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VAHighVulnerable-system availability: A successful attack can cause a major loss.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-252
A

Official authority intelligence

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

CERT-FR · French · CERTFR-2026-AVI-0800Multiples vulnérabilités dans CPython

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

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
exploit-intelligence-tech-preview/vulnerability-analysis-rhel9 as a component of Exploit Intelligence; rhaii/model-opt-cuda-rhel9 as a component of Red Hat AI Inference Server; rhaii/vllm-cpu-rhel9 as a component of Red Hat AI Inference Server; rhaii/vllm-cuda-rhel9 as a component of Red Hat AI Inference Server; rhaii/vllm-gaudi-rhel9 as a component of Red Hat AI Inference Server; rhaii/vllm-neuron-rhel9 as a component of Red Hat AI Inference Server; rhaii/vllm-rocm-rhel9 as a component of Red Hat AI Inference Server; rhaii/vllm-spyre-rhel9 as a component of Red Hat AI Inference Server; rhaii/vllm-tpu-rhel9 as a component of Red Hat AI Inference Server; rhaiis/model-opt-cuda-rhel9 as a component of Red Hat AI Inference Server; rhaiis/vllm-cpu-rhel9 as a component of Red Hat AI Inference Server; rhaiis/vllm-cuda-rhel9 as a component of Red Hat AI Inference Server; rhaiis/vllm-neuron-rhel9 as a component of Red Hat AI Inference Server; rhaiis/vllm-rocm-rhel9 as a component of Red Hat AI Inference Server; rhaiis/vllm-spyre-rhel9 as a component of Red Hat AI Inference Server; rhaiis/vllm-tpu-rhel9 as a component of Red Hat AI Inference Server; 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; python3.14 as a component of Red Hat Enterprise Linux 10; python3.14-debug as a component of Red Hat Enterprise Linux 10; python3.14-devel as a component of Red Hat Enterprise Linux 10; python3.14-freethreading as a component of Red Hat Enterprise Linux 10; python3.14-freethreading-debug as a component of Red Hat Enterprise Linux 10; and 189 more
Fixed
python3-11-main@aarch64 as a component of Red Hat Hardened Images; python3-11-main@src as a component of Red Hat Hardened Images; python3-11-main@x86_64 as a component of Red Hat Hardened Images; python3-12-main@aarch64 as a component of Red Hat Hardened Images; python3-12-main@src as a component of Red Hat Hardened Images; python3-12-main@x86_64 as a component of Red Hat Hardened Images; python3-13-main@aarch64 as a component of Red Hat Hardened Images; python3-13-main@src as a component of Red Hat Hardened Images; python3-13-main@x86_64 as a component of Red Hat Hardened Images; python3-14-main@aarch64 as a component of Red Hat Hardened Images; python3-14-main@noarch as a component of Red Hat Hardened Images; python3-14-main@src as a component of Red Hat Hardened Images; python3-14-main@x86_64 as a component of Red Hat Hardened Images
Action
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
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 23 Jun 2026 · Last source change 13 Aug 2026, 00:28 UTC · CWE-252 · Unchecked Return Value

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-2026-38630
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-2026-38630↗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-2026-11972 · cve.blacktree.nl