CVE-2026-56852 — x/text
CVE-2026-56852 is a CWE-835 vulnerability in golang.org/x/text. A fix is available for golang.org/x/text — see the affected versions and patch details below.
Infinite loop on invalid input in golang.org/x/text
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-56852.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
golang.org/x/textReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
A norm.Iter can enter an infinite loop when handling input containing invalid UTF-8 bytes.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | golang.org/x/text | all versions | 0.39.0go get golang.org/x/text@v0.39.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for golang.org/x/text, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update golang.org/x/text to 0.39.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-56852 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Important: This flaw in the `golang.org/x/text` library can lead to a denial of service. An attacker could provide specially crafted invalid UTF-8 input to an application using the affected `norm.Iter` functionality, causing it to enter an infinite loop and become unresponsive.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.Source: Red Hat security advisory for CVE-2026-56852 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 10 | podman-7:5.8.2-9.el10_2 | RHSA-2026:70201 |
| Red Hat Enterprise Linux 8 | rhc-1:0.2.5-11.el8_10 | RHSA-2026:69258 |
| RHEM 1.1 for RHEL 10 | flightctl-0:1.1.4-1.el10em | RHSA-2026:68334 |
| RHEM 1.2 for RHEL 10 | flightctl-0:1.2.1-1.el10 | RHSA-2026:68335 |
| Cert Manager support for Red Hat OpenShift release 1.19 | cert-manager/cert-manager-operator-rhel9:1788348522 | RHSA-2026:63135 |
| Cert Manager support for Red Hat OpenShift release 1.19 | cert-manager/jetstack-cert-manager-acmesolver-rhel9:1788348571 | RHSA-2026:63138 |
| Cert Manager support for Red Hat OpenShift release 1.20 | cert-manager/jetstack-cert-manager-rhel9:1790223279 | RHSA-2026:72394 |
| Cert Manager support for Red Hat OpenShift release 1.20 | cert-manager/cert-manager-istio-csr-rhel9:1790223719 | RHSA-2026:72395 |
Frequently Asked Questions
Is CVE-2026-56852 in your dependencies?
Find it across Go, including transitive dependencies.