# CVE-2026-6637: PostgreSQL refint allows stack buffer overflow and SQL injection > Unprivileged users can execute arbitrary code via stack overflow or SQL injection in the refint module, requiring specific application configurations. - **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 14 May 2026 - **Updated:** 15 May 2026 - **Also known as:** ALPINE-CVE-2026-6637, AZL-86837, BELL-CVE-2026-6637, BIT-postgresql-2026-6637, DEBIAN-CVE-2026-6637, ECHO-e69f-5ef2-55d4, GHSA-96xx-m79q-xh44, JLSEC-2026-607, MINI-3xq4-rjp9-wx66, MINI-634f-pq4w-9vhg, MINI-8q9w-26qp-wxvj, MINI-mvwh-ccp7-r475, MINI-v44q-56x3-m3pj, MINI-wcmp-39jv-whwj, RHSA-2026:50119, RHSA-2026:50811, UBUNTU-CVE-2026-6637 ## What is CVE-2026-6637? CVE-2026-6637 is a high-severity SQL injection vulnerability in Postgresql Postgresql, published on 14 May 2026. Any signed-in user can exploit it over the network, with no action from the victim. ### Official description Stack buffer overflow in PostgreSQL module "refint" allows an unprivileged database user to execute arbitrary code as the operating system user running the database. A distinct attack is possible if the application declares a user-controlled column as a "refint" cascade primary key and facilitates user-controlled updates to that column. In that case, a SQL injection allows a primary key update value provider to execute arbitrary SQL as the database user performing the primary key update. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected. Weakness: CWE-89 (Improper Neutralization of Special Elements used in an SQL Command), CWE-121 (Stack-based Buffer Overflow) ## Which versions are affected by CVE-2026-6637? 1 open source package ship an affected version, including postgresql. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `postgresql` | Bitnami | All versions | 14.23.0, 15.18.0, 16.14.0, 17.10.0, 18.4.0 | | `postgresql` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-contrib` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-contrib-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-debugsource` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-docs-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-plperl` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-plperl-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-plpython3` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-plpython3-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-pltcl` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-pltcl-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-private-libs` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-private-libs-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-server` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-server-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-server-devel-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-test-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-upgrade` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-upgrade-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql-upgrade-devel-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:13.23-1.el9_2.3 | | `postgresql` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-contrib` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-contrib-debuginfo` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-debuginfo` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-debugsource` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-docs-debuginfo` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-plperl` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-plperl-debuginfo` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-plpython3` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-plpython3-debuginfo` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-pltcl` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-pltcl-debuginfo` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-private-libs` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-private-libs-debuginfo` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-server` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-server-debuginfo` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-server-devel-debuginfo` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | | `postgresql-test-debuginfo` | Red Hat:rhel_eus:9.6::appstream | All versions | 0:13.23-1.el9_6.3 | Products: Postgresql Postgresql. ## How do I fix CVE-2026-6637? Upgrade postgresql to a fixed version for your release line: 14.23.0, 15.18.0, 16.14.0 or 17.10.0. ## Is CVE-2026-6637 being exploited? There is no known exploitation of CVE-2026-6637 in the wild and no public exploit code. ## Other vulnerabilities in Postgresql Postgresql - [CVE-2013-1902](https://insights.sbomify.com/CVE-2013-1902/): Information disclosure in n/a (critical 10.0) - [CVE-2013-1903](https://insights.sbomify.com/CVE-2013-1903/): Information disclosure in n/a (critical 10.0) - [CVE-2007-3279](https://insights.sbomify.com/CVE-2007-3279/): Privilege escalation in n/a (critical 10.0) - [CVE-2002-1399](https://insights.sbomify.com/CVE-2002-1399/): Integer overflow in n/a (critical 10.0) - [CVE-2016-3065](https://insights.sbomify.com/CVE-2016-3065/): Information disclosure in n/a (critical 9.1) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-6637 and fix it if it is affected. What it is: CVE-2026-6637 is a high-severity SQL injection vulnerability in Postgresql Postgresql, published on 14 May 2026. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-6637 in the wild and no public exploit code. Affected packages and fixed versions: - postgresql (Bitnami): affected all versions; fixed in 14.23.0, 15.18.0, 16.14.0, 17.10.0, 18.4.0 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-2026-6637/ (Markdown: https://insights.sbomify.com/CVE-2026-6637/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-6637 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-6637 - OSV: https://osv.dev/vulnerability/CVE-2026-6637 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-6637/ Summaries are generated and may contain mistakes; the official description above is the record.