CVE-2026-56852 Infinite loop on invalid input in golang.org/x/text
High 7.5
Published
Updated
Check this codebase for CVE-2026-56852 and fix it if it is affected.
What it is: CVE-2026-56852 is a high-severity denial of service vulnerability in golang.org/x/text/unicode/norm, published on 21 Jul 2026. 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-2026-56852 in the wild and no public exploit code.
Affected packages and fixed versions:
- golang.org/x/text (Go): affected all versions; fixed in 0.39.0
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-2026-56852/ (Markdown: https://insights.sbomify.com/CVE-2026-56852/index.md)
An attacker can cause a denial of service by triggering an infinite loop in the Go text normalization library with invalid UTF-8 input.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-56852?
CVE-2026-56852 is a high-severity denial of service vulnerability in golang.org/x/text/unicode/norm, published on 21 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A norm.Iter can enter an infinite loop when handling input containing invalid UTF-8 bytes.
Weakness: CWE-835
Which versions are affected by CVE-2026-56852?
1 open source package ship an affected version, including golang.org/x/text.
| Package | Affected | Fixed in |
|---|---|---|
golang.org/x/text Go | All versions | 0.39.0 |
Linux distribution packages (39)
rhc Red Hat:enterprise_linux:8::appstream | All versions | 1:0.2.5-11.el8_10 |
rhc-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 1:0.2.5-11.el8_10 |
rhc-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 1:0.2.5-11.el8_10 |
buildah Red Hat:hummingbird:1 | All versions | 0:1.44.0-3.3.hum1 |
caddy Red Hat:hummingbird:1 | All versions | 0:2.11.4-0.3.hum1 |
cosign Red Hat:hummingbird:1 | All versions | 0:3.1.2-0.3.hum1 |
etcd Red Hat:hummingbird:1 | All versions | 0:3.7.0-0.3.hum1 |
go-fdo-client Red Hat:hummingbird:1 | All versions | 0:1.0.0-2.1.hum1 |
go-fdo-server Red Hat:hummingbird:1 | All versions | 0:1.0.1-0.5.hum1 |
go-fdo-server-manufacturer Red Hat:hummingbird:1 | All versions | 0:1.0.1-0.5.hum1 |
go-fdo-server-owner Red Hat:hummingbird:1 | All versions | 0:1.0.1-0.5.hum1 |
go-fdo-server-rendezvous Red Hat:hummingbird:1 | All versions | 0:1.0.1-0.5.hum1 |
golang1.25 Red Hat:hummingbird:1 | All versions | 0:1.25.12-1.1.hum1 |
golang1.25-bin Red Hat:hummingbird:1 | All versions | 0:1.25.12-1.1.hum1 |
golang1.25-docs Red Hat:hummingbird:1 | All versions | 0:1.25.12-1.1.hum1 |
golang1.25-misc Red Hat:hummingbird:1 | All versions | 0:1.25.12-1.1.hum1 |
golang1.25-src Red Hat:hummingbird:1 | All versions | 0:1.25.12-1.1.hum1 |
golang1.25-tests Red Hat:hummingbird:1 | All versions | 0:1.25.12-1.1.hum1 |
golang1.26 Red Hat:hummingbird:1 | All versions | 0:1.26.5-0.1.1.hum1 |
golang1.26-bin Red Hat:hummingbird:1 | All versions | 0:1.26.5-0.1.1.hum1 |
golang1.26-docs Red Hat:hummingbird:1 | All versions | 0:1.26.5-0.1.1.hum1 |
golang1.26-misc Red Hat:hummingbird:1 | All versions | 0:1.26.5-0.1.1.hum1 |
golang1.26-src Red Hat:hummingbird:1 | All versions | 0:1.26.5-0.1.1.hum1 |
golang1.26-tests Red Hat:hummingbird:1 | All versions | 0:1.26.5-0.1.1.hum1 |
grype Red Hat:hummingbird:1 | All versions | 0:0.116.0-0.1.hum1 |
hugo Red Hat:hummingbird:1 | All versions | 0:0.164.0-0.1.2.hum1 |
jaeger Red Hat:hummingbird:1 | All versions | 0:2.20.0-0.2.hum1 |
kubernetes1.35 Red Hat:hummingbird:1 | All versions | 0:1.35.6-2.1.hum1 |
kubernetes1.35-client Red Hat:hummingbird:1 | All versions | 0:1.35.6-2.1.hum1 |
kubernetes1.35-kubeadm Red Hat:hummingbird:1 | All versions | 0:1.35.6-2.1.hum1 |
kubernetes1.35-systemd Red Hat:hummingbird:1 | All versions | 0:1.35.6-2.1.hum1 |
kubernetes1.36 Red Hat:hummingbird:1 | All versions | 0:1.36.2-6.1.hum1 |
kubernetes1.36-client Red Hat:hummingbird:1 | All versions | 0:1.36.2-6.1.hum1 |
kubernetes1.36-kubeadm Red Hat:hummingbird:1 | All versions | 0:1.36.2-6.1.hum1 |
kubernetes1.36-systemd Red Hat:hummingbird:1 | All versions | 0:1.36.2-6.1.hum1 |
oauth2-proxy Red Hat:hummingbird:1 | All versions | 0:7.15.3-0.3.hum1 |
opentofu1.10 Red Hat:hummingbird:1 | All versions | 0:1.10.10-0.3.hum1 |
opentofu1.11 Red Hat:hummingbird:1 | All versions | 0:1.11.13-0.2.hum1 |
opentofu1.12 Red Hat:hummingbird:1 | All versions | 0:1.12.5-0.2.hum1 |
How do I fix CVE-2026-56852?
Upgrade golang.org/x/text to 0.39.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-56852 being exploited?
There is no known exploitation of CVE-2026-56852 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as AZL-93075, AZL-93078, AZL-93081, AZL-93087, AZL-93093, AZL-93099 and 1711 more.