# CVE-2024-39936: Race condition in n/a > A race condition in Qt's HTTP2 implementation allows security checks to execute before encryption is confirmed, potentially bypassing security controls. - **Severity:** High 8.6 (`CVSS:3.1/AC:L/AV:N/A:N/C:H/I:N/PR:N/S:C/UI:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 4 Jul 2024 - **Updated:** 29 Nov 2025 - **Also known as:** ALSA-2024:4617, ALSA-2024:4623, AZL-43192, DEBIAN-CVE-2024-39936, DLA-4387-1, GHSA-8gfm-8wff-rjvj, OESA-2026-2841, OESA-2026-2842, RHSA-2024:4617, RHSA-2024:4621, RHSA-2024:4623, RHSA-2024:4638, RHSA-2024:4639, RHSA-2024:4644, RHSA-2024:4645, RHSA-2024:4646, RHSA-2024:4647, RLSA-2024:4617, RLSA-2024:4623, UBUNTU-CVE-2024-39936, openSUSE-SU-2024:14114-1, openSUSE-SU-2024:14215-1 ## What is CVE-2024-39936? CVE-2024-39936 is a high-severity vulnerability in Qt Qt, published on 4 Jul 2024. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description An issue was discovered in HTTP2 in Qt before 5.15.18, 6.x before 6.2.13, 6.3.x through 6.5.x before 6.5.7, and 6.6.x through 6.7.x before 6.7.3. Code to make security-relevant decisions about an established connection may execute too early, because the encrypted() signal has not yet been emitted and processed.. Weakness: CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition) ## Which versions are affected by CVE-2024-39936? It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `qt5-qtbase` | AlmaLinux:8 | All versions | 5.15.3-8.el8_10 | | `qt5-qtbase-common` | AlmaLinux:8 | All versions | 5.15.3-8.el8_10 | | `qt5-qtbase-devel` | AlmaLinux:8 | All versions | 5.15.3-8.el8_10 | | `qt5-qtbase-examples` | AlmaLinux:8 | All versions | 5.15.3-8.el8_10 | | `qt5-qtbase-gui` | AlmaLinux:8 | All versions | 5.15.3-8.el8_10 | | `qt5-qtbase-mysql` | AlmaLinux:8 | All versions | 5.15.3-8.el8_10 | | `qt5-qtbase-odbc` | AlmaLinux:8 | All versions | 5.15.3-8.el8_10 | | `qt5-qtbase-postgresql` | AlmaLinux:8 | All versions | 5.15.3-8.el8_10 | | `qt5-qtbase-private-devel` | AlmaLinux:8 | All versions | 5.15.3-8.el8_10 | | `qt5-qtbase-static` | AlmaLinux:8 | All versions | 5.15.3-8.el8_10 | | `qt5-qtbase` | AlmaLinux:9 | All versions | 5.15.9-10.el9_4 | | `qt5-qtbase-common` | AlmaLinux:9 | All versions | 5.15.9-10.el9_4 | | `qt5-qtbase-devel` | AlmaLinux:9 | All versions | 5.15.9-10.el9_4 | | `qt5-qtbase-examples` | AlmaLinux:9 | All versions | 5.15.9-10.el9_4 | | `qt5-qtbase-gui` | AlmaLinux:9 | All versions | 5.15.9-10.el9_4 | | `qt5-qtbase-mysql` | AlmaLinux:9 | All versions | 5.15.9-10.el9_4 | | `qt5-qtbase-odbc` | AlmaLinux:9 | All versions | 5.15.9-10.el9_4 | | `qt5-qtbase-postgresql` | AlmaLinux:9 | All versions | 5.15.9-10.el9_4 | | `qt5-qtbase-private-devel` | AlmaLinux:9 | All versions | 5.15.9-10.el9_4 | | `qt5-qtbase-static` | AlmaLinux:9 | All versions | 5.15.9-10.el9_4 | | `qt5-qtbase` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-common` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-devel` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-devel-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-examples` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-examples-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-gui` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-gui-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-mysql` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-mysql-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-odbc` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-odbc-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-postgresql` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-postgresql-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-private-devel` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-tests-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:5.15.3-8.el8_10 | | `qt5-qtbase-debugsource` | Red Hat:enterprise_linux:8::crb | All versions | 0:5.15.3-8.el8_10 | Products: Qt Qt. ## How do I fix CVE-2024-39936? Upgrade to a fixed version. ## Is CVE-2024-39936 being exploited? There is no known exploitation of CVE-2024-39936 in the wild and no public exploit code. ## Other vulnerabilities in Qt Qt - [CVE-2020-12267](https://insights.sbomify.com/CVE-2020-12267/): Use after free in n/a (critical 9.8) - [CVE-2017-10904](https://insights.sbomify.com/CVE-2017-10904/): Command injection in Qt for Android (critical 9.8) - [CVE-2011-3194](https://insights.sbomify.com/CVE-2011-3194/): Memory corruption in n/a (critical 9.3) - [CVE-2022-40983](https://insights.sbomify.com/CVE-2022-40983/): Integer overflow in Qt (high 8.8) - [CVE-2022-43591](https://insights.sbomify.com/CVE-2022-43591/): Memory corruption in Qt (high 8.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2024-39936 and fix it if it is affected. What it is: CVE-2024-39936 is a high-severity vulnerability in Qt Qt, published on 4 Jul 2024. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2024-39936 in the wild and no public exploit code. Affected product: Qt Qt. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2024-39936/ (Markdown: https://insights.sbomify.com/CVE-2024-39936/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-39936 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-39936 - OSV: https://osv.dev/vulnerability/CVE-2024-39936 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-39936/ Summaries are generated and may contain mistakes; the official description above is the record.