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CVE-2026-58102 JONASBN CVE debrief

CVE-2026-58102 is a heap out-of-bounds read vulnerability in Crypt::OpenSSL::X509 versions before 2.1.3 for Perl. The vulnerability occurs when building the extension hash via extensions(), extensions_by_long_name(), extensions_by_oid(), or has_extension_oid(). The code passes OBJ_obj2txt()'s return value as the hash-key length, which is the OID's full text length rather than the bytes written to the fixed-size buffer (129 bytes). This causes a read past the allocation, exposing adjacent heap memory as the returned hash key. The vulnerability is exploitable via a long certificate extension OID in hv_exts. Users of Crypt::OpenSSL::X509 versions before 2.1.3 for Perl should be aware of this vulnerability and take steps to mitigate it.

Vendor
JONASBN
Product
Crypt::OpenSSL::X509
CVSS
CRITICAL 9.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-13
Original CVE updated
2026-08-11
Advisory published
2026-07-13
Advisory updated
2026-08-11

Who should care

Users of Crypt::OpenSSL::X509 versions before 2.1.3 for Perl should be aware of this vulnerability and take steps to mitigate it. This may include upgrading to version 2.1.3 or later, or implementing compensating controls to limit the impact of a potential exploit. Affected operator, platform, vulnerability-management, and security-team impact should be reviewed.

Technical summary

The vulnerability is caused by the use of OBJ_obj2txt()'s return value as the hash-key length, which is the OID's full text length rather than the bytes written to the fixed-size buffer (129 bytes). This causes a read past the allocation, exposing adjacent heap memory as the returned hash key. The vulnerability is exploitable via a long certificate extension OID in hv_exts. Affected product deployments should be reviewed for exposure, and owners should be assigned for follow-up.

Defensive priority

High

Recommended defensive actions

  • Upgrade to Crypt::OpenSSL::X509 version 2.1.3 or later
  • Implement compensating controls to limit the impact of a potential exploit
  • Monitor for and respond to potential exploitation attempts
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
  • Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
  • Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record was published on 2026-07-13T23:16:47.127Z and has not been modified since then. The NVD entry is currently Received. There is limited information available about the vulnerability, and defenders should verify the affected scope and severity. The vulnerability is caused by a heap out-of-bounds read in Crypt::OpenSSL::X509 versions before 2.1.3 for Perl.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-58102 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-58102

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-58102 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-58102

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://github.com/dsully/perl-crypt-openssl-x509/commit/757289bfce095455c104d4adfe9312e7b339620f.patch

    9b29abf9-4ab0-4765-b253-1875cd9b441e

  • Source reference

    Unverified legacy reference

    URL: https://metacpan.org/release/JONASBN/Crypt-OpenSSL-X509-2.1.3/source/Changes.md

    9b29abf9-4ab0-4765-b253-1875cd9b441e

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.