What is CVE-2026-58101?
Crypt::OpenSSL::X509 versions before 2.1.3 for Perl allow denial of service via NULL pointer dereference. X509V3_EXT_d2i(ext) returns NULL when an extension's DER value fails to parse. basicC, ia5string, and auth_att dereference its result without a NULL check. keyid_data also dereferences akid->keyid, which is NULL for an empty AKI SEQUENCE (DER 30 00) even when the parse succeeds. A caller invoking an affected helper on an extension from an untrusted certificate triggers a SIGSEGV that crashes the Perl process.
The record classifies CVE-2026-58101 under weakness class CWE-476. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 84 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.5 — HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS (FIRST)
- 0.1% probability of exploitation in the next 30 days, higher than 1.3% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 3.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-07-13, last modified 2026-07-14
Is CVE-2026-58101 being exploited?
It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.
Affected products and versions
- JONASBN: Crypt::OpenSSL::X509
How to fix CVE-2026-58101
No vendor patch reference has been recorded for CVE-2026-58101 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-58101
No threat campaign in the Threadlinqs corpus currently references CVE-2026-58101, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.