Security readout for executives and security teams
Plain-English summary
FreeBSD applications may corrupt memory when converting attacker-controlled text through affected ISO-2022 iconv modules. A character can exceed the six-byte stack buffer by up to four bytes. Successful exploitation could potentially compromise confidentiality, integrity, and availability, reflected in the supplied CVSS 9.8 rating.
Executive priority
Treat as an urgent critical patch-and-exposure investigation. Prioritize internet-facing or privileged applications performing character-set conversion. Systems without affected FreeBSD releases or without untrusted ISO-2022 iconv data paths are lower priority, but should be documented as such.
Technical view
The ISO-2022 module allocates MB_LEN_MAX, six bytes, for intermediate character output, although some variants require up to ten bytes. Converting untrusted input to or from an affected encoding can therefore cause a stack-based buffer overflow of up to four bytes in iconv(3).
Likely exposure
Exposure requires an application on FreeBSD 14.3, 14.4, 15.0, or 15.1 to process untrusted data through an affected ISO-2022 iconv conversion. The bundle does not identify specific applications, enabled variants, deployment prevalence, or fixed releases.
Exploitation context
The supplied record is not listed in KEV, and the source bundle provides no evidence of active exploitation or a public exploit. The network-accessible CVSS vector assumes a vulnerable application exposes attacker-controlled conversion without privileges or user interaction; actual reachability depends on application behavior.
Researcher notes
CWE-121 applies. The overwrite is described as stack-based and limited to four bytes, but exploitability depends on compiler protections, calling context, encoding variant, and surrounding stack layout. The bundle does not name affected variants, patched versions, proof-of-concept availability, or observed indicators.
Mitigation direction
- Review the FreeBSD advisory and apply its vendor-supported correction when available for each affected release.
- Identify applications converting untrusted content through iconv(3), prioritizing network-facing and privileged services.
- Until corrected, prevent untrusted input from reaching affected ISO-2022 conversions where operationally feasible.
- Use compensating isolation for conversion services that cannot be promptly corrected.
Validation and detection
- Confirm FreeBSD versions across hosts, images, appliances, and recovery environments.
- Trace application data flows for untrusted input passed to or from ISO-2022 iconv modules.
- Verify installed corrections against the FreeBSD advisory rather than relying only on application package versions.
- Run existing defensive regression tests with sanitized malformed inputs; avoid production crash testing.
- Monitor relevant services for abnormal termination or memory-corruption indicators after conversion requests.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-121: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-58082 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://security.freebsd.org/advisories/FreeBSD-SA-26:49.iconv.ascCVE reference, freebsd · vendor-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Stack-based Buffer Overflow
Stack-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.