Vulnerability · Published Sep 23, 2026 · Assigned by Qt
CVE-2026-78253Denial-of-service (stack-exhaustion) vulnerability in QXmlStreamReader::readElementText() impacts Qt
Low 2.3
In plain English
A low-severity security flaw in qt from qt. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 4.0)2.3Low
Exploit odds (30 days)0.4%top 62.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Uncontrolled recursion in QXmlStreamReader::readElementText() in Qt Group Qt allows attackers to cause a denial of service (application crash via stack exhaustion) via a crafted XML document.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | qt6-base | no fix listed | DEBIAN-CVE-2026-78253 |
| Debian:13 | qt6-base | no fix listed | DEBIAN-CVE-2026-78253 |
| Debian:14 | qt6-base | 6.11.2+dfsg-5 | DEBIAN-CVE-2026-78253 |
| Debian:12 | qtbase-opensource-src | no fix listed | DEBIAN-CVE-2026-78253 |
| Debian:13 | qtbase-opensource-src | no fix listed | DEBIAN-CVE-2026-78253 |
| Debian:14 | qtbase-opensource-src | 5.15.19+dfsg-6 | DEBIAN-CVE-2026-78253 |
| Ubuntu:22.04:LTS | qt6-base | no fix listed | UBUNTU-CVE-2026-78253 |
| Ubuntu:24.04:LTS | qt6-base | no fix listed | UBUNTU-CVE-2026-78253 |
| Ubuntu:26.04:LTS | qt6-base | no fix listed | UBUNTU-CVE-2026-78253 |
| Ubuntu:26.10 | qt6-base | no fix listed | UBUNTU-CVE-2026-78253 |
| Ubuntu:26.04:LTS | qtbase-opensource-src | no fix listed | UBUNTU-CVE-2026-78253 |
| Ubuntu:26.10 | qtbase-opensource-src | no fix listed | UBUNTU-CVE-2026-78253 |
Affected products (as reported)
Weakness: CWE-674 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/S:N/AU:N/R:U/RE:L/U:Green
References
- dev patch patch