VulnerabilityPublished 9 Apr 2026Updated 29 Jul 2026

CVE-2026-24880: Tomcat6 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Affects tomcat6Source GCVE Database

Authoritative record:CVE-2026-24880· High 7.5

Not known to be exploited · CVSS 7.5 High · fixed in 11.0.20 : patch tomcat6 soon.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.6% chance of exploitation in 30 days – higher than 52% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 11.0.20

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 9 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTStomcat10`pkg:deb/ubuntu/tomcat10?arch=source&distro=resolute`Other threats	Affected =10.1.40-1ubuntu1 =10.1.40-1ubuntu1.26.04.1 =10.1.55-1ubuntu2~26.04.1	Fixed in–
Ubuntu 26.04 LTStomcat9`pkg:deb/ubuntu/tomcat9?arch=source&distro=resolute`Other threats	Affected 9.0.95-1ubuntu1 – 9.0.118-1~26.04.1 5 affected builds	Fixed in–
Ubuntu 26.04 LTStomcat11`pkg:deb/ubuntu/tomcat11?arch=source&distro=resolute`Other threats	Affected 11.0.6-1 – 11.0.22-2ubuntu2~26.04.1 6 affected builds	Fixed in–
Ubuntu 25.10tomcat10`pkg:deb/ubuntu/tomcat10?arch=source&distro=questing`Other threats	Affected 10.1.35-1 – 10.1.40-1ubuntu1.25.10.1 4 affected builds	Fixed in–
Ubuntu 25.10tomcat11`pkg:deb/ubuntu/tomcat11?arch=source&distro=questing`Other threats	Affected =11.0.6-1	Fixed in–
Ubuntu 25.10tomcat9`pkg:deb/ubuntu/tomcat9?arch=source&distro=questing`Other threats	Affected 9.0.70-2ubuntu1.1 – 9.0.95-1ubuntu1.1 5 affected builds	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Apache Tomcat via invalid chunk extension. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.18, from 10.1.0-M1 through 10.1.52, from 9.0.0.M1 through 9.0.115, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other, unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.20, 10.1.52 or 9.0.116, which fix the issue.

References

Community reviews

Loading reviews…