GO-2026-5942 BIT-golang-2026-46600 CVE-2026-46600
Parsing an invalid SVCB or HTTPS RR can panic in golang.org/x/net/dns/dnsmessage
High
Go
- Severity
- 7.5 / 10
- High · CVSS 3.1
- Exploit chance (EPSS)
- 0.55%
- Chance of exploitation in the next 30 days. Higher than 45.99% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-125 Out-of-bounds Read
- Fix
- Available
- 2 packages have a fixed version
Description
Parsing an invalid SVCB or HTTPS RR can panic when the size of a parameter value overflows the message buffer.
Affected versions
Go
| Package | Vulnerable | Fixed in |
|---|---|---|
| golang.org/x/net | < 0.56.0 |
0.56.0 |
| stdlib | >= 1.26.0-0, < 1.26.6>= 1.27.0-0, < 1.27.0-rc.3 |
1.26.61.27.0-rc.3 |
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 → 0.56.0
- go
go get golang.org/x/net@v0.56.0 && go mod tidy
stdlib Go → 1.27.0-rc.3
- go
go get stdlib@v1.27.0-rc.3 && 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-125: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How to prevent it
- Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.
- Architecture and Design: Use a language that provides appropriate memory abstractions.
References
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 |
| CVE-2020-0601 Certificate validation bypass on Windows in crypto/x509 | High Known exploited | Also affects stdlib |
| 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 |
| RUSTSEC-2026-0382 Distrust compromised intermediate certificates in crypto/x509 | Medium | Also affects stdlib |
| GO-2026-6613 HTTP/1 server connection desynchronization after 2xx CONNECT response in net/http | High | Also affects stdlib |
| GO-2026-6609 Lack of limit on size of parsed Range headers in net/http | High | Also affects stdlib |
Credits: Mundur (https://github.com/M0nd0R)
MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.
Check your repos with MergeHarbor