How severe is CVE-2026-58186?

CVE-2026-58186 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-58186 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-58186?

CVE-2026-58186 affects Apache Traffic Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-58186?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-58186 published?

CVE-2026-58186 was published on 2026-07-29 and last updated on 2026-07-31.

CVE-2026-58186

CVE-2026-58186 is a high-severity vulnerability in Apache Traffic Server with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.2
EPSS exploit prediction: 1% (44th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Apache Traffic Server
Published: 2026-07-29
Last modified: 2026-07-31

Description

The Apache Traffic Server webp_transform plugin can decode unsafely and serve mislabeled, cacheable responses. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.9, from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3. Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.

Frequently asked questions

What is CVE-2026-58186?: The Apache Traffic Server webp_transform plugin can decode unsafely and serve mislabeled, cacheable responses. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.9, from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3. Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.
How severe is CVE-2026-58186?: CVE-2026-58186 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-58186 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-58186?: CVE-2026-58186 affects Apache Traffic Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-58186?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-58186 published?: CVE-2026-58186 was published on 2026-07-29 and last updated on 2026-07-31.

References

https://lists.apache.org/thread/5prl9glcm9g2swnq9hqxvnokylm1gr6d

Affected products (1)

cpe:2.3:a:apache:traffic_server:*:*:*:*:*:*:*:*

More vulnerabilities in Apache Traffic Server

CVE-2026-58162 — Critical (CVSS 10.0): The Apache Traffic Server certifier plugin generates certificates based on attacker-controlled client SNI. This issue…
CVE-2026-58150 — Critical (CVSS 10.0): Apache Traffic Server does not reject Transfer-Encoding in HTTP/2 requests, allowing downgrade request smuggling. This…
CVE-2026-57834 — Critical (CVSS 10.0): Apache Traffic Server allows request smuggling if chunked messages are malformed. This issue affects Apache Traffic…
CVE-2026-33267 — Critical (CVSS 10.0): Improper Input Validation vulnerability in Apache Traffic Server. This issue affects Apache Traffic Server: from 9.2.0…
CVE-2014-3525 — Critical (CVSS 10.0): Unspecified vulnerability in Apache Traffic Server 3.x through 3.2.5, 4.x before 4.2.1.1, and 5.x before 5.0.1 has…
CVE-2021-43082 — Critical (CVSS 9.8): Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in the stats-over-http plugin of…

All CVEs affecting Apache Traffic Server →

Other CWE-20 (Improper Input Validation) vulnerabilities

CVE-2026-48056 — Critical (CVSS 10.0): Streambert is a cross-platform Electron Desktop App to stream and download video content. Versions prior to 2.5.0…
CVE-2026-33267 — Critical (CVSS 10.0): Improper Input Validation vulnerability in Apache Traffic Server. This issue affects Apache Traffic Server: from 9.2.0…
CVE-2026-47668 — Critical (CVSS 10.0): DbGate is cross-platform database manager. In versions 7.1.8 and prior, DbGate's JSON script runner (`POST…
CVE-2026-16117 — Critical (CVSS 10.0): Impact: @fastify/http-proxy versions up to and including 11.5.0 fail to rewrite the request prefix when the prefix…
CVE-2026-48316 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48281 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…

Browse all CWE-20 (Improper Input Validation) vulnerabilities →