CVE-2026-65927

Apache Tomcat: RewriteValve [N] restarts at the second rule and may bypass access control

HIGH

7.5

CVSS Score

Published: August 25, 2026 at 09:53 PM UTC

Updated: August 27, 2026 at 03:31 PM UTC

1 product affected across 1 vendorTomcat

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Severity

HIGH7.5

Exploit prediction

EPSS 0.7%

SSVC

No known exploit

Description

Off-by-one Error vulnerability in Apache Tomcat impacting the [N] flag on the rewrite valves causes rewrite processing to restart at the second rule rather than the first rule. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121 which fix the issue.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Tomcat · Apache

95%

10.1.0 ≤ v < 10.1.5810.1.0-M1 ≤ v ≤ 10.1.5711.0.0 ≤ v < 11.0.2511.0.0-M1 ≤ v ≤ 11.0.248.5.0 ≤ v ≤ 8.5.1008.5.0 ≤ v < 9.0.1219.0.0.M1 ≤ v ≤ 9.0.12010.1.0-M1 11.0.0-M1 8.5.0 9.0.0.M1

Affected range stops below 10.1.58, so it looks safe — our inference, not a vendor statement

Affected range stops below 11.0.25, so it looks safe — our inference, not a vendor statement

Vendor states this is fixed in 7.0.0 (unaffected)

Affected range stops below 9.0.121, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://lists.apache.org/thread/st1dx1zyn5y7ny2s0sscmh6lrv3worr4

References (2)

Vendor AdvisoryMailing List

Source: cverecord

https://lists.apache.org/thread/st1dx1zyn5y7ny2s0sscmh6lrv3worr4

Third Party AdvisoryMailing List

Source: af854a3a-2127-422b-91ae-364da2661108

http://www.openwall.com/lists/oss-security/2026/08/26/5

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHCISA-ADP

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusANALYZED

CWE

CWE-193

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