TI-2026-79595 Aliases CVE-2026-16762 GHSA-3gxv-qxph-7hg3

Denial of service in Qt QXmlStreamReader XML parsing

MEDIUM 44CWE-407Published 2026-10-23 · Updated 2026-10-23

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Partial Red Hat: 6 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-407.

Summary

Qt from 4.3.0 before 6.8.9 and from 6.9.0 before 6.11.2 is affected. Inefficient algorithmic complexity (CWE-407) in QXmlStreamReader causes disproportionate CPU consumption while parsing crafted XML documents. A remote attacker who can supply XML to an application that uses QXmlStreamReader can make that application unresponsive, with no authentication or user interaction beyond ingesting the input.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

An attacker able to supply a crafted XML document to an application using QXmlStreamReader can cause disproportionate CPU consumption during parsing, making the application unresponsive (denial of service). Exploitation requires only that the application parse attacker-influenced XML; no authentication, privileges, or user interaction beyond ingesting the input are needed. There is no loss of confidentiality or integrity — no data disclosure, data modification, or code execution — and the impact is contained to the affected process.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00516 44th percentileScored 2026-11-07

Fix Partial qt (qt): 6.8.9, 6.11.2Red Hat: 6 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
qt	qt	4.3.0 to before 6.8.9; 6.9.0 to before 6.11.2	6.8.9, 6.11.2	Patch available	CNA

qt Vendorqt Affected 4.3.0 to before 6.8.9; 6.9.0 to before 6.11.2 Fixed in 6.8.9, 6.11.2 Patch available CNA

Remediation

Upgrade Qt to 6.8.9 or 6.11.2. Red Hat has no available plan for Red Hat Enterprise Linux 6, 7, 8, 9 and 10 or Red Hat Hardened Images.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Fix · CNA qt (qt) Fixed in 6.8.9, 6.11.2

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix yet
Red Hat Enterprise Linux 6	Affected	No fix yet
Red Hat Enterprise Linux 7	Affected	No fix yet
Red Hat Enterprise Linux 8	Affected	No fix yet
Red Hat Enterprise Linux 9	Affected	No fix yet
Red Hat Hardened Images	Affected	No fix yet

Not affected: 1 product

Red Hat Hardened Images

Timeline

2026-10-23 Threatist record created from CVE-2026-16762
2026-10-23 Alias added: GHSA-3gxv-qxph-7hg3
2026-10-23 CISA SSVC decision points changed
2026-11-06 Affected versions changed · Red Hat
2026-11-06 CVSS score added · Red Hat

References

Patch 2

Advisory 1

https://wiki.qt.io/List_of_known_vulnerabilities_in_Qt_products#CVE-2026-16762:

TI-2024-23902 QAbstractOAuth in Qt Network Authorization in Qt before 5.15.17, 6.x before 6.2.13, 6.3.x… CVSS 3.1CRITICAL 9.8
TI-2022-21359 Heap-based buffer overflow in Qt CVSS 3.1HIGH 8.8
TI-2022-19524 Integer overflow in Qt CVSS 3.1HIGH 8.8
TI-2023-18997 In Qt before 5.15.15, 6.x before 6.2.9, and 6.3.x through 6.5.x before 6.5.2, there can… CVSS 3.1HIGH 7.5
TI-2021-09305 Integer Overflow vulnerability in qsvghandler.cpp in Qt qtsvg versions 5.15.1, 6.0.0… CVSS 3.1MEDIUM 5.5
TI-2023-28356 An issue was discovered in the HTTP2 implementation in Qt before 5.15.17, 6.x before… CVSS 3.1CRITICAL 9.8

See all 106 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences