GO-2026-4559 CVE-2026-27141
Sending certain HTTP/2 frames can cause a server to panic in golang.org/x/net
High
Go
- Severity
- 7.5 / 10
- High · CVSS 3.1
- Exploit chance (EPSS)
- 0.57%
- Chance of exploitation in the next 30 days. Higher than 47.14% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-476 NULL Pointer Dereference
- Fix
0.51.0- Upgrade golang.org/x/net to this version or later
Description
Due to missing nil check, sending 0x0a-0x0f HTTP/2 frames will cause a running server to panic
Affected versions
Go
| Package | Vulnerable | Fixed in |
|---|---|---|
| golang.org/x/net | >= 0.50.0, < 0.51.0 |
0.51.0 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
golang.org/x/net Go → 0.51.0
- go
go get golang.org/x/net@v0.51.0 && go mod tidy
Severity breakdown
CVSS 3.1 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Weakness
CWE-476: NULL Pointer Dereference
The product dereferences a pointer that it expects to be valid but is NULL.
How to prevent it
- Implementation: For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished [REF-1484].
- Requirements: Select a programming language that is not susceptible to these issues.
- Implementation: Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
- Architecture and Design: Identify all variables and data stores that receive information from external sources, and apply input validation to make sure that they are only initialized to expected values.
- Implementation: Explicitly initialize all variables and other data stores, either during declaration or just before the first usage.
References
Advisories
Fixes and patches
Issue reports
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-4374-p667-p6c8 HTTP/2 rapid reset can cause excessive work in net/http | High Known exploited | Also affects golang.org/x/net |
| GHSA-qppj-fm5r-hxr3 HTTP/2 Stream Cancellation Attack | Medium Known exploited | Also affects golang.org/x/net |
| GO-2026-6866 Check all ancestor namespace transitions when rendering raw text in html in golang.org/x/net | Not rated yet | Also affects golang.org/x/net |
| GO-2026-6860 Avoid quadratic complexity when coalescing text nodes in html in golang.org/x/net | Not rated yet | Also affects golang.org/x/net |
| GO-2026-6617 HTTP/2 server crash due to HPACK encoder race in net/http | High | Also affects golang.org/x/net |
| GO-2026-6612 Double flow control refund on HTTP/2 server streams in net/http | Critical | Also affects golang.org/x/net |
| GO-2026-6611 Excessive CPU consumption from repeated initial window changes in net/http | High | Also affects golang.org/x/net |
| GO-2026-6610 HTTP/2 transport accepts malformed framing-related headers in net/http | High | Also affects golang.org/x/net |
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