How severe is CVE-2026-58156?

CVE-2026-58156 has a CVSS 3.x base score of 4.9, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-58156 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-58156?

CVE-2026-58156 affects Apache Traffic Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-58156?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-58156 published?

CVE-2026-58156 was published on 2026-07-29 and last updated on 2026-08-03.

CVE-2026-58156

CVE-2026-58156 is a medium-severity vulnerability in Apache Traffic Server with a CVSS 3.x base score of 4.9. 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-863.

Key facts

Severity: Medium (CVSS 3.x base score 4.9)
CVSS v4: 6.3
EPSS exploit prediction: 0% (13th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Apache Traffic Server
Published: 2026-07-29
Last modified: 2026-08-03

Description

Apache Traffic Server mis-parses ports in URLs and userinfo, allowing port-based access-control bypass. 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-2026-58156?: Apache Traffic Server mis-parses ports in URLs and userinfo, allowing port-based access-control bypass. 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-2026-58156?: CVE-2026-58156 has a CVSS 3.x base score of 4.9, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-58156 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-58156?: CVE-2026-58156 affects Apache Traffic Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-58156?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-58156 published?: CVE-2026-58156 was published on 2026-07-29 and last updated on 2026-08-03.

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-863 (Incorrect Authorization) vulnerabilities

CVE-2026-69555 — Critical (CVSS 10.0): Incorrect authorization in Azure Arc allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-71398 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) is affected by an Incorrect Authorization vulnerability that could result in arbitrary…
CVE-2026-27302 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) is affected by an Incorrect Authorization vulnerability that could result in arbitrary…
CVE-2026-48449 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) is affected by an Incorrect Authorization vulnerability that could result in arbitrary…
CVE-2026-48286 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) versions 7.4.3 build 9396 and earlier are affected by an Incorrect Authorization…
CVE-2026-48303 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) versions 7.4.3 build 9394 and earlier are affected by an Incorrect Authorization…

Browse all CWE-863 (Incorrect Authorization) vulnerabilities →