# CVE-2026-73066: Tesseract: Heap out-of-bounds write in LSTM Convolve layer via crafted .traineddata > An attacker can achieve code execution by providing a crafted .traineddata file that triggers an integer overflow and heap out-of-bounds write in the Tesseract OCR engine. - **Severity:** Medium 6.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Local or same network only - **Victim action needed:** A user has to click or open something - **Fix available:** Yes - **Published:** 11 Aug 2026 - **Updated:** 11 Aug 2026 - **Also known as:** ALSA-2026:67831, ALSA-2026:67832, DEBIAN-CVE-2026-73066, ECHO-bf17-e4d0-1453, GHSA-7j76-5rq5-5jg8, RHSA-2026:67830, RHSA-2026:67831, RHSA-2026:67832, RHSA-2026:69111, RHSA-2026:69495, RHSA-2026:71566, RHSA-2026:71567, RHSA-2026:71568, RHSA-2026:72280, RLSA-2026:67830, RLSA-2026:67831, RLSA-2026:67832, UBUNTU-CVE-2026-73066 ## What is CVE-2026-73066? CVE-2026-73066 is a medium-severity vulnerability in tesseract-ocr tesseract, published on 11 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link. ### Official description Tesseract is an open source OCR engine. Prior to 5.5.3, a crafted .traineddata LSTM model component loaded through Tesseract's deserializer can cause an unchecked signed integer multiplication in Convolve::DeSerialize in src/lstm/convolve.cpp to wrap the convolution output-channel count, undersizing the forward-pass output buffer while writes use the unwrapped element count and causing a heap out-of-bounds write during OCR recognition. This issue is fixed in version 5.5.3. Weakness: CWE-787 (Out-of-bounds Write) ## Which versions are affected by CVE-2026-73066? | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `tesseract` | AlmaLinux:8 | All versions | 4.1.1-3.el8_10 | | `tesseract-devel` | AlmaLinux:8 | All versions | 4.1.1-3.el8_10 | | `tesseract` | AlmaLinux:9 | All versions | 4.1.1-8.el9_8 | | `tesseract-devel` | AlmaLinux:9 | All versions | 4.1.1-8.el9_8 | | `tesseract` | Red Hat:enterprise_linux:10.2 | All versions | 0:5.3.4-7.el10_2 | | `tesseract-debuginfo` | Red Hat:enterprise_linux:10.2 | All versions | 0:5.3.4-7.el10_2 | | `tesseract-debugsource` | Red Hat:enterprise_linux:10.2 | All versions | 0:5.3.4-7.el10_2 | | `tesseract-devel` | Red Hat:enterprise_linux:10.2 | All versions | 0:5.3.4-7.el10_2 | | `tesseract-tools-debuginfo` | Red Hat:enterprise_linux:10.2 | All versions | 0:5.3.4-7.el10_2 | | `tesseract` | Red Hat:enterprise_linux:8::appstream | All versions | 0:4.1.1-3.el8_10 | | `tesseract-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:4.1.1-3.el8_10 | | `tesseract-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 0:4.1.1-3.el8_10 | | `tesseract-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:4.1.1-3.el8_10 | | `tesseract-debugsource` | Red Hat:enterprise_linux:8::crb | All versions | 0:4.1.1-3.el8_10 | | `tesseract-devel` | Red Hat:enterprise_linux:8::crb | All versions | 0:4.1.1-3.el8_10 | | `tesseract` | Red Hat:enterprise_linux:9::appstream | All versions | 0:4.1.1-8.el9_8 | | `tesseract-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:4.1.1-8.el9_8 | | `tesseract-debugsource` | Red Hat:enterprise_linux:9::appstream | All versions | 0:4.1.1-8.el9_8 | | `tesseract-tools-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:4.1.1-8.el9_8 | | `tesseract-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 0:4.1.1-8.el9_8 | | `tesseract-debugsource` | Red Hat:enterprise_linux:9::crb | All versions | 0:4.1.1-8.el9_8 | | `tesseract-devel` | Red Hat:enterprise_linux:9::crb | All versions | 0:4.1.1-8.el9_8 | | `tesseract-tools-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 0:4.1.1-8.el9_8 | | `tesseract` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:5.3.4-6.el10_0.1 | | `tesseract-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:5.3.4-6.el10_0.1 | | `tesseract-debugsource` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:5.3.4-6.el10_0.1 | | `tesseract-devel` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:5.3.4-6.el10_0.1 | | `tesseract-tools-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:5.3.4-6.el10_0.1 | | `tesseract` | Red Hat:rhel_aus:8.6::appstream | All versions | 0:4.1.1-2.el8_6.1 | | `tesseract-debuginfo` | Red Hat:rhel_aus:8.6::appstream | All versions | 0:4.1.1-2.el8_6.1 | | `tesseract-debugsource` | Red Hat:rhel_aus:8.6::appstream | All versions | 0:4.1.1-2.el8_6.1 | | `tesseract` | Red Hat:rhel_e4s:8.8::appstream | All versions | 0:4.1.1-2.el8_8.1 | | `tesseract-debuginfo` | Red Hat:rhel_e4s:8.8::appstream | All versions | 0:4.1.1-2.el8_8.1 | | `tesseract-debugsource` | Red Hat:rhel_e4s:8.8::appstream | All versions | 0:4.1.1-2.el8_8.1 | | `tesseract` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:4.1.1-7.el9_2.1 | | `tesseract-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:4.1.1-7.el9_2.1 | | `tesseract-debugsource` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:4.1.1-7.el9_2.1 | | `tesseract-tools-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:4.1.1-7.el9_2.1 | | `tesseract` | Red Hat:rhel_e4s:9.4::appstream | All versions | 0:4.1.1-7.el9_4.1 | | `tesseract-debuginfo` | Red Hat:rhel_e4s:9.4::appstream | All versions | 0:4.1.1-7.el9_4.1 | ## How do I fix CVE-2026-73066? Upgrade to a fixed version. ## Is CVE-2026-73066 being exploited? There is no known exploitation of CVE-2026-73066 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-73066 and fix it if it is affected. What it is: CVE-2026-73066 is a medium-severity vulnerability in tesseract-ocr tesseract, published on 11 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link. Exploitation: There is no known exploitation of CVE-2026-73066 in the wild and no public exploit code. Affected product: tesseract-ocr tesseract. 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-2026-73066/ (Markdown: https://insights.sbomify.com/CVE-2026-73066/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-73066 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-73066 - OSV: https://osv.dev/vulnerability/CVE-2026-73066 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-73066/ Summaries are generated and may contain mistakes; the official description above is the record.