CVE-2026-32280 Unexpected work during chain building in crypto/x509
Attackers can cause denial of service in Go applications by supplying excessive intermediate certificates during chain building.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-32280?
CVE-2026-32280 is a high-severity denial of service vulnerability in Golang Go, published on 8 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
During chain building, the amount of work that is done is not correctly limited when a large number of intermediate certificates are passed in VerifyOptions.Intermediates, which can lead to a denial of service. This affects both direct users of crypto/x509 and users of crypto/tls.
Weakness: CWE-770
Which versions are affected by CVE-2026-32280?
2 open source packages ship an affected version, including golang and stdlib. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
golang Bitnami | All versions | 1.25.9, 1.26.2 |
stdlib Go | All versions | 1.25.9, 1.26.2 |
Linux distribution packages (10)
rhc Red Hat:enterprise_linux:10.2 | All versions | 1:0.3.8-5.el10_2 |
rhc-debuginfo Red Hat:enterprise_linux:10.2 | All versions | 1:0.3.8-5.el10_2 |
rhc-debugsource Red Hat:enterprise_linux:10.2 | All versions | 1:0.3.8-5.el10_2 |
runc Red Hat:openshift:4.19::el9 | All versions | 4:1.2.5-6.rhaos4.19.el9 |
runc-debuginfo Red Hat:openshift:4.19::el9 | All versions | 4:1.2.5-6.rhaos4.19.el9 |
runc-debugsource Red Hat:openshift:4.19::el9 | All versions | 4:1.2.5-6.rhaos4.19.el9 |
skopeo Red Hat:openshift:4.19::el9 | All versions | 2:1.18.1-6.rhaos4.19.el9 |
skopeo-debuginfo Red Hat:openshift:4.19::el9 | All versions | 2:1.18.1-6.rhaos4.19.el9 |
skopeo-debugsource Red Hat:openshift:4.19::el9 | All versions | 2:1.18.1-6.rhaos4.19.el9 |
skopeo-tests Red Hat:openshift:4.19::el9 | All versions | 2:1.18.1-6.rhaos4.19.el9 |
Products include Golang Go.
How do I fix CVE-2026-32280?
Upgrade golang to a fixed version for your release line: 1.25.9 or 1.26.2.
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-2026-32280 being exploited?
There is no known exploitation of CVE-2026-32280 in the wild and no public exploit code.
Other vulnerabilities in Golang Go
- CVE-2020-0601 Microsoft Windows CryptoAPI Spoofing
- CVE-2026-27143 Missing bound checks can lead to memory corruption in safe Go in cmd/compile
- CVE-2024-24790 Unexpected behavior from Is methods for IPv4-mapped IPv6 addresses in net/netip
- CVE-2023-39320 Arbitrary code execution via go.mod toolchain directive in cmd/go
- CVE-2023-24540 Improper handling of JavaScript whitespace in html/template
Sources
Also known as AZL-98658, BELL-CVE-2026-32280, BIT-golang-2026-32280, CLEANSTART-2026-CN39298, CLEANSTART-2026-DR35313, CLEANSTART-2026-HN25684 and 654 more.