CVE-2025-5455Network attack vector

Application abort via valueless charset assertion

Published Jun 2, 2025 · Updated Jul 29, 2026

Denial of service in Qt Framework allows remote attackers to abort assertion-enabled applications through malformed data URLs. The private qDecodeDataUrl() function in QtCore passes a valueless charset parameter into an assertion-sensitive decoding path instead of rejecting it. Affected QtCore builds are reachable through QTextDocument, QNetworkReply, or application code, but the abort occurs only when assertions are enabled and a caller processes the malformed URL.

CVSS severity8.4
High
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Qt Framework allows remote attackers to abort assertion-enabled applications through malformed data URLs. The private qDecodeDataUrl() function in QtCore passes a valueless charset parameter into an assertion-sensitive decoding path instead of rejecting it. Affected QtCore builds are reachable through QTextDocument, QNetworkReply, or application code, but the abort occurs only when assertions are enabled and a caller processes the malformed URL.

The record

CVE
CVE-2025-5455
Published
Jun 2, 2025
Updated
Jul 29, 2026
Vendor
The Qt Company
Product
Qt Framework
Classifications
CWE-20, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=5.15.18
  2. Affected versionversion=6.0.0 <=6.5.8
  3. Affected versionversion=6.6.0 <=6.8.3
  4. Affected versionversion=6.9.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Qt Company · Qt Frameworkversion=0 <=5.15.18; version=6.0.0 <=6.5.8; version=6.6.0 <=6.8.3; version=6.9.0

Published CVSS scores

8.4The Qt CompanyCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H/R:U/RE:M/U:Clear

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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