Answer in brief
CVE-2026-42327 records a Unknown severity vulnerability in rust-openssl has undefined behavior in X509Ref::ocsp_responders for certificates with non-UTF-8 OCSP URLs. The current sources do not mark it as known exploited. The current feed maps openssl (crates.io). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps openssl (crates.io). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| opensslcrates.io | >=0.9.7 <0.10.79 | 0.10.79 |
Published upstream
May 4, 2026
Evidence: source:osv:source_dates:source-dates:recordSource modified
Nov 10, 2026
Evidence: source:osv:source_dates:source-dates:recordFirst seen by HOL
Nov 10, 2026
`X509Ref::ocsp_responders` returns the OCSP responder URLs from a certificate's Authority Information Access extension as `OpensslString` values, which dereference to `str` without validating the bytes. OpenSSL does not require these IA5String values to be ASCII, so for a certificate with non-UTF-8 bytes in an OCSP access location, safe code ends up holding a `&str` that is not valid UTF-8, which is undefined behavior. Certificates often come from untrusted peers. `ocsp_responders` was added in 0.9.7. 0.10.79 checks each URL and returns an error if it is not valid UTF-8.
Quoted source text, attributed separately from HOL analysis.