CVE-2026-58186
ATS webp_transform decodes unsafely, serving mislabeled cacheable responses.
Is CVE-2026-58186 being exploited?
Not confirmed. CVE-2026-58186 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.42% probability of exploitation in the next 30 days.
How severe is CVE-2026-58186?
CVE-2026-58186 is rated High with a CVSS score of 8.2. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-58186?
Yes. A fix has been recorded for CVE-2026-58186. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-58186 affect?
CVE-2026-58186 affects Apache Traffic Server 8.0.0-8.1.9, Apache Traffic Server 9.0.0-9.2.14, Apache Traffic Server 10.0.0-10.1.3, webp_transform plugin. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-58186?
Upgrade to ATS 9.2.15 or 10.1.4; disable webp_transform if you cannot patch.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Enables cache poisoning and delivery of mislabeled or attacker-controlled content to clients, enabling content spoofing, data leakage or phishing.
Patch when possible
- affected>= 8.0.0 and <= 8.1.9
- affected>= 9.0.0 and <= 9.2.14
- affected>= 10.0.0 and <= 10.1.3
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.