BlackTreeCVE Intelligence
← Back to the CVE catalogue
Full vulnerability report · 2025
CVE-2025-5399High confidence

WebSocket endless loop

curl · curl

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.

Fix not verified
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Critical, raised one band.upgradedsince 9 Jun 2025

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 1.38% for the current model date.

Compensating controls

  • 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 curl curl and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  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, Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

7 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 · maincurlVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.8.14.1-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.22v3.22 · maincurlVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.8.14.1-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.21v3.21 · maincurlVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.8.14.1-r0Alpine Security Database ↗Source updated 3 Oct 2026
Debian trixietrixie · sourcecurlVendor fix publishedDebian records a fixed source-package version for this release.8.14.1-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourcecurlNot affectedDebian marks this release not affected (fixed-version marker 0).Not published in this feedDebian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourcecurlVendor fix publishedDebian records a fixed source-package version for this release.8.14.1-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourcecurlVendor fix publishedDebian records a fixed source-package version for this release.8.14.1-1Debian Security Tracker ↗Source updated 5 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-2025-5399 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitycurl: libcurl: WebSocket endless loop
66 known not affected

The vendor explicitly states that these products are not affected by this CVE.

  • confidential-compute-attestation-tech-preview/trustee-rhel9 as a component of Confidential Compute Attestation
  • cargo as a component of Red Hat Enterprise Linux 10
  • clippy as a component of Red Hat Enterprise Linux 10
  • curl as a component of Red Hat Enterprise Linux 10
  • curl.src as a component of Red Hat Enterprise Linux 10
  • libcurl as a component of Red Hat Enterprise Linux 10
  • libcurl-devel as a component of Red Hat Enterprise Linux 10
  • libcurl-minimal as a component of Red Hat Enterprise Linux 10
  • rust-analyzer as a component of Red Hat Enterprise Linux 10
  • rust-debugger-common as a component of Red Hat Enterprise Linux 10
  • rust-doc as a component of Red Hat Enterprise Linux 10
  • rust-gdb as a component of Red Hat Enterprise Linux 10
Summary
A flaw was found in libcurl's WebSocket handling. This vulnerability allows a malicious server to cause an applicaiton level denial of service (DoS) by triggering an infinite busy-loop, effectively trapping the application thread, via a specially crafted WebSocket packet when "auto-pong" is enabled.
Remediation
No remediation text is recorded.
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-2025-17371

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

Fix not verified
01

What, why and how

Due to a mistake in libcurl's WebSocket code, a malicious server can send a particularly crafted packet which makes libcurl get trapped in an endless busy-loop. There is no other way for the application to escape or exit this loop other than killing the thread/process. This might be used to DoS libcurl-using application.

What

Due to a mistake in libcurl's WebSocket code, a malicious server can send a particularly crafted packet which makes libcurl get trapped in an endless busy-loop. There is no other way for the application to escape or exit this loop other than killing the thread/process. This might be used to DoS libcurl-using application.

Why

A malformed condition prevents a loop from making progress or terminating, allowing resource exhaustion.

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

Due to a mistake in libcurl's WebSocket code, a malicious server can send a particularly crafted packet which makes libcurl get trapped in an endless busy-loop. There is no other way for the application to escape or exit this loop other than killing the thread/process. This might be used to DoS libcurl-using application.

Why

A malformed condition prevents a loop from making progress or terminating, allowing resource exhaustion.

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.
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 → Loop with Unreachable Exit Condition ('Infinite Loop') → 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
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-835 ↗

CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop'). The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.

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.
NetworkUnauthenticatedCWE-835Public exploit reference
A

Official authority intelligence

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

BSI · German · WID-SEC-2025-2363Oracle MySQL: Mehrere Schwachstellen

Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle MySQL ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.

Official advisory ↗
BSI · German · WID-SEC-2025-2360Oracle Communications Applications: Mehrere Schwachstellen

Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle Communications Applications ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.

Official advisory ↗
BSI · German · WID-SEC-2025-1567Oracle MySQL: Mehrere Schwachstellen

Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle MySQL ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.

Official advisory ↗
BSI · German · WID-SEC-2025-1228cURL: Schwachstelle ermöglicht Denial of Service

Ein entfernter, anonymer Angreifer kann eine Schwachstelle in cURL ausnutzen, um einen Denial of Service Angriff durchzuführen.

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-0907Multiples vulnérabilités dans Oracle MySQL

ERecord?id=CVE-2025-53045 Référence CVE CVE-2025-53053 https://www.cve.org/CVERecord?id=CVE-2025-53053 Référence CVE CVE-2025-53054 https://www.cve.org/CVERecord?id=CVE-2025-53054 Référence CVE CVE-2025-53062 https://www.cve.org/CVERecord?id=CVE-2025-53062 Référence CVE CVE-2025-53067 https://www.cve.org/CVERecord?id=CVE-2025-53067 Référence CVE CVE-2025-53069 https://www.cve.org/CVERecord?id=CVE-2025-53069 Référence CVE CVE-2025-5318 https://www.cve.org/CVERecord?id=CVE-2025-5318 Référence CVE CVE-2025-5351 https://www.cve.org/CVERecord?id=CVE-2025-5351 Référence CVE CVE-2025-5372 https://www.cve.org/CVERecord?id=CVE-2025-5372 Référence CVE CVE-2025-5399 https://www.cve.org/CVERecord?id=CVE-2025-5399 Référence CVE CVE-2025-5449 https://www.cve.org/CVERecord?id=CVE-2025-5449 Référence CVE CVE-2025-5987 https://www.cve.org/CVERecord?id=CVE-2025-5987 Référence CVE CVE-2025-6965 https://www.cve.org/CVERecord?id=CVE-2025-6965 Gestion détaillée du document le 22 octobre 2025 Version initiale Alertes Avis Bulletins d’actualités Mentions légales Conditions générales À propos Contact cyber.gouv.fr service-public.fr legifrance.gouv.fr info.gouv.fr france.fr info.gouv.fr/risques Premier Ministre / Secrétariat Général de la Défense et de la Sécurité Nationale / Agence nationale de la sécurité des systèm

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-0621Multiples vulnérabilités dans les produits Tenable

De multiples vulnérabilités ont été découvertes dans Tenable Identity Exposure. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, un déni de service à distance et une atteinte à l'intégrité des données.

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-0601Multiples vulnérabilités dans Oracle MySQL

d?id=CVE-2025-50098 Référence CVE CVE-2025-50099 https://www.cve.org/CVERecord?id=CVE-2025-50099 Référence CVE CVE-2025-50100 https://www.cve.org/CVERecord?id=CVE-2025-50100 Référence CVE CVE-2025-50101 https://www.cve.org/CVERecord?id=CVE-2025-50101 Référence CVE CVE-2025-50102 https://www.cve.org/CVERecord?id=CVE-2025-50102 Référence CVE CVE-2025-50103 https://www.cve.org/CVERecord?id=CVE-2025-50103 Référence CVE CVE-2025-50104 https://www.cve.org/CVERecord?id=CVE-2025-50104 Référence CVE CVE-2025-53023 https://www.cve.org/CVERecord?id=CVE-2025-53023 Référence CVE CVE-2025-53032 https://www.cve.org/CVERecord?id=CVE-2025-53032 Référence CVE CVE-2025-5399 https://www.cve.org/CVERecord?id=CVE-2025-5399 Gestion détaillée du document le 18 juillet 2025 Version initiale Alertes Avis Bulletins d’actualités Mentions légales Conditions générales À propos Contact cyber.gouv.fr service-public.fr legifrance.gouv.fr info.gouv.fr france.fr info.gouv.fr/risques Premier Ministre / Secrétariat Général de la Défense et de la Sécurité Nationale / Agence nationale de la sécurité des systèmes d'information

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-0476Vulnérabilité dans cURL

Une vulnérabilité a été découverte dans cURL. Elle permet à un attaquant de provoquer un déni de service à distance.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2025-010315Haxx の cURL における無限ループに関する脆弱性

Haxx の cURL には、無限ループに関する脆弱性が存在します。

Official advisory ↗
NCSC-NL · Dutch · NCSC-2025-0339Kwetsbaarheden verholpen in Oracle MySQL

Multiple vulnerabilities in Oracle MySQL Server and Cluster, along with libcurl's WebSocket code, allow for various denial of service attacks, with CVSS scores ranging from 4.3 to 7.5.

Official advisory ↗
NCSC-NL · Dutch · NCSC-2025-0330Kwetsbaarheden verholpen in Oracle Communications producten

Multiple vulnerabilities in Oracle MySQL Server and Cluster, along with libcurl's WebSocket code, allow for various denial of service attacks, with CVSS scores ranging from 4.3 to 7.5.

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.
Fix not verified
Affected
curl: 8.14.0 ≤ 8.14.0, 8.13.0 ≤ 8.13.0
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
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 7 Jun 2025 · Last source change 9 Jun 2025, 13:20 UTC · CWE-835 · Loop with Unreachable Exit Condition ('Infinite Loop')

CVE recordCVE.org · 5.1
CVSS sourceCISA ADP
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-2025-17371
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

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
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-2025-5399 · cve.blacktree.nl