Out-of-Bounds Read in Jonasbn (CVE-2026-58102)
Summary
Vulnerability in Jonasbn (CVE-2026-58102). Confidential information can be exposed externally.
Original description
The description as published by the source.
Crypt::OpenSSL::X509 versions before 2.1.3 for Perl allow a heap out-of-bounds read via a long certificate extension OID in hv_exts.
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; because that value is the OID's full text length rather than the bytes written to the fixed-size buffer (129 bytes), an OID whose text is longer than the 129-byte buffer causes a read past the allocation, exposing adjacent heap memory as the returned hash key. extensions_by_name() uses the static shortname path and is not affected.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-58102 has been found in Jonasbn.
Confidential information can be exposed externally. CVSS score: 9.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Jonasbn CVE-2026-58102" on the vendor's site.
CVE-2026-58102 (Jonasbn) — CWE-125 / CVSS v3 9.1
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Out-of-bounds read (CWE-125) exists in Jonasbn.
Check the vendor advisory for the affected versions of Jonasbn.
Severity: Critical (CVSS 9.1/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Jonasbn' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Jonasbn' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Jonasbnを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-58102 libcrypt-openssl-x509-perl
- Ubuntu UBUNTU-CVE-2026-58102 libcrypt-openssl-x509-perl
References
- patch github.com
- web metacpan.org
- web nvd.nist.gov
- web github.com