What is CVE-2026-58088?

CVE-2026-58088 is Race condition in ELF core dump segment counting. The supplied enrichment data classifies it as Remote Code Exec mapped to CWE-362 CWE-362; CWE-787 CWE-787.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Exploitation is reported, but no independent confirmation is available in the sources we have. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-58088 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

1 public PoC repositories reported; 1 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with EDR process telemetry, host service logs where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-58088 using CVSS null, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

Remote Code Execpublic exploit

CVE-2026-58088

CVE-2026-58088 — Race condition in ELF core dump segment counting

The ELF core dump code counted the number of dumpable VM map entries, allocated a buffer for the corresponding program headers, then iterated over the map a second time to populate them. A process sharing the address space via rfork(2) can mutate the map between the two passes, causing the second pass to write program headers past the end of the buffer. An unprivileged local user sharing an address space with a process that dumps core can trigger an out-of-bounds write on the kernel heap, potentially leading to privilege escalation.

Published Aug 19, 2026Updated Aug 19, 2026Sources: NVD, FreeBSD (CNA), GitHub, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Reported

not confirmed by CISA

EPSS

ahead of 0% of scored CVEs

Affects

FreeBSD

3 products listed

CVSS base

Unscored

no source published a base score

Remediation

The vendor's own words where we have them.

Upgrade FreeBSD to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
FreeBSD	FreeBSD	15.1-RELEASE	Vulnerable
FreeBSD	FreeBSD	15.0-RELEASE	Vulnerable
FreeBSD	FreeBSD	14.4-RELEASE	Vulnerable

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

DoS: Resource Consumption (CPU)
DoS: Resource Consumption (Memory)
DoS: Resource Consumption (Other)
DoS: Crash, Exit, or Restart

Mitigation: In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.

CWE-787 · Out-of-bounds Write

Modify Memory
DoS: Crash, Exit, or Restart
Execute Unauthorized Code or Commands::

Mitigation: Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.

Weakness & attack patterns

CWE-362
CWE-787

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-26 · Leveraging Race ConditionsCAPEC-29 · Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

1 of the 1 sampled are weaponized

Social mentions

Posts naming this CVE. Attention, not evidence of exploitation — it spikes on disclosure and decays whether or not anything is exploited.

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Monitor for scanner or exploit-pattern traffic after 1 public PoC repositories were reported.

EDR process telemetryhost service logs

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Initial · CVE published
Aug 19, 2026 · NVD

Source activity

Readings a source repeats on a schedule, counted rather than listed.

1×Tweets · 1 time tweeted.Aug 12, 2026 · SOCRadar CTI

References

1 on the record

security.freebsd.org/advisories/FreeBSD-SA-26:55.elf.asc
Vendor Advisory

Elsewhere on this site

FreeBSDevery CVE for this vendor
Remote Code Execsame class
CWE-362other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2026-58088 is Race condition in ELF core dump segment counting, a unscored vulnerability affecting FreeBSD from FreeBSD. The current evidence does not list it in CISA KEV, and the exploit status is: Exploitation is reported, but no independent confirmation is available in the sources we have. Public exploit evidence is: 1 public PoC repositories reported; 1 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS null describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.