CVE-2026-56851 Panic parsing crafted input in x/text/secure/precis in golang.org/x/text
An attacker can cause a denial of service by triggering a panic in the Go text library's Nickname profile via crafted 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-2026-56851?
CVE-2026-56851 is a high-severity denial of service vulnerability in golang.org/x/text/secure/precis, published on 7 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The Nickname profile can panic with an out-of-bounds slice error when transforming crafted input into a short destination buffer.
Weakness: CWE-787
Which versions are affected by CVE-2026-56851?
1 open source package ship an affected version, including golang.org/x/text.
| Package | Affected | Fixed in |
|---|---|---|
golang.org/x/text Go | All versions | 0.41.0 |
Linux distribution packages (12)
caddy Red Hat:hummingbird:1 | All versions | 0:2.11.7-0.1.hum1 |
distribution Red Hat:hummingbird:1 | All versions | 0:3.1.2-0.1.hum1 |
etcd Red Hat:hummingbird:1 | All versions | 0:3.7.2-0.1.hum1 |
fulcio Red Hat:hummingbird:1 | All versions | 0:1.9.0-0.1.hum1 |
golang1.27 Red Hat:hummingbird:1 | All versions | 0:1.27.1-2.hum1 |
golang1.27-bin Red Hat:hummingbird:1 | All versions | 0:1.27.1-2.hum1 |
golang1.27-docs Red Hat:hummingbird:1 | All versions | 0:1.27.1-2.hum1 |
golang1.27-misc Red Hat:hummingbird:1 | All versions | 0:1.27.1-2.hum1 |
golang1.27-src Red Hat:hummingbird:1 | All versions | 0:1.27.1-2.hum1 |
golang1.27-tests Red Hat:hummingbird:1 | All versions | 0:1.27.1-2.hum1 |
opentelemetry-collector Red Hat:hummingbird:1 | All versions | 0:0.162.0-0.1.hum1 |
opentelemetry-collector-k8s Red Hat:hummingbird:1 | All versions | 0:0.162.0-0.1.hum1 |
How do I fix CVE-2026-56851?
Upgrade golang.org/x/text to 0.41.0 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-2026-56851 being exploited?
There is no known exploitation of CVE-2026-56851 in the wild and no public exploit code.
Sources
Also known as AZL-107610, CLEANSTART-2026-AF18367, CLEANSTART-2026-CY51593, CLEANSTART-2026-DB41831, CLEANSTART-2026-EI53048, CLEANSTART-2026-II79171 and 1372 more.