CVE-2026-111815

HIGH 7.8

Published 2026-10-21 · Last modified 2026-10-23

Apache Traffic Server can resume a TLS session across SNI virtual hosts without re-verifying a client certificate required by the resumed host's verify_client STRICT policy. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0. Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.

ELEVATED IMPACT

Severe if exploited (CVSS 7.8), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.2%chance of exploitation in 30 days · 14th percentile

○ In CISA KEV ○ Catalogued PoC

Impact if exploited

7.8CVSS 4.0 · HIGH

ConfidentialityNone
IntegrityNone
AvailabilityNone

What an attacker needs

✓Access: Reachable over the network — no local access needed
✓Privileges: No account or privileges required
✓User interaction: No user interaction needed
✓Complexity: No special conditions — reliably repeatable
✓Requirements: No special attack requirements

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

No public PoC is currently catalogued.

Search for new PoCs

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Tracked sources are checked daily for recent CVEs, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Data snapshot: 2026-10-26T13:52:32.101Z

Affected

Vendors Apache Software Foundation

Products Apache Traffic Server

Weakness (CWE)

CWE-295: Improper Certificate Validation

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N

References and research data (JSON)

All CVSS metrics

CRITICAL 10 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
HIGH 7.8 v4.0 · CNA Primary
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
HIGH 7.8 v4.0 · NVD Secondary
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CRITICAL 10 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

References

Advisories

https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc vendor-advisoryCVE record · apache · Updated 2026-10-21T19:13:55.811Z
NVD · CVE-2026-111815 · Updated 2026-10-23T12:18:09.333
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-107500 ADVISORYEUVD · EUVD-2026-107500

Sources: NVD · CVE.org · EPSS