VulnerabilityPublished 21 Apr 2026Updated 22 May 2026

CVE-2026-25542: tektoncd pipeline · Incorrect Regular Expression

Affects tektoncd pipelineSource CVE Database V5

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Not known to be exploited · CVSS 6.5 Medium · fixed in 1.11.1 : update tektoncd pipeline when convenient.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 18% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.11.1, 1.9.3, 1.6.2 +3

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
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: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
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 21 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 29 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
tektoncdpipeline	Affected >=1.10.0 <1.11.1	Fixed in 1.11.1
tektoncdpipeline	Affected >=1.7.0 <1.9.3	Fixed in 1.9.3
tektoncdpipeline	Affected >=1.4.0 <1.6.2	Fixed in 1.6.2
tektoncdpipeline	Affected >=1.2.0 <1.3.4	Fixed in 1.3.4
tektoncdpipeline	Affected >=0.43.0 <1.0.2	Fixed in 1.0.2
Gogithub.com/tektoncd/pipeline`pkg:golang/github.com/tektoncd/pipeline`Other threats	Affected <0.43.0 >=0.43.0 <1.0.2 >=1.0.2 <1.3.4 >=1.3.4 <1.6.2 >=1.6.2 <1.9.3 >=1.9.3 <1.11.1	Fixed in 0.43.0 1.0.2 1.3.4 1.6.2 1.9.3 1.11.1

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

AI-suggested

Fixed versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1 of Tekton Pipelines address this vulnerability. Users should upgrade to one of these versions or later to remediate the issue. Patch status is not explicitly stated beyond these fixed versions; therefore, verify with the vendor advisory for the latest remediation guidance. No alternative mitigations are indicated in the advisory.

Description

Tekton Pipelines project provides k8s-style resources for declaring CI/CD-style pipelines. Starting in version 0.43.0 and prior to versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1, trusted resources verification policies match a resource source string (refSource.URI) against spec.resources[].pattern using regexp.MatchString. In Go, regexp.MatchString reports a match if the pattern matches anywhere in the string, so common unanchored patterns (including examples in tekton documentation) can be bypassed by attacker-controlled source strings that contain the trusted pattern as a substring. This can cause an unintended policy match and change which verification mode/keys apply. Versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1 fix the issue.

Impact

An attacker controlling resource source strings can bypass trusted resource verification policies by exploiting the unanchored regular expression matching. This can cause the system to apply incorrect verification modes or keys, potentially allowing unauthorized or malicious resources to be treated as trusted. The CVSS score of 6.5 reflects a medium severity with no confidentiality or availability impact but a high integrity impact. No known exploits in the wild have been reported.

Summary

Tekton Pipelines uses Go's regexp.MatchString function to verify trusted resources by matching a resource source string against configured patterns. Because regexp.MatchString returns true if the pattern matches anywhere in the string, unanchored patterns can be bypassed by crafted source strings containing the pattern as a substring. This leads to unintended policy matches that may change the verification mode or keys applied to resources. The vulnerability affects multiple version ranges before fixed releases 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1, which address this issue.

CWE-185Incorrect Regular Expression (opens in a new tab)
Base weakness
The product specifies a regular expression in a way that causes data to be improperly matched or compared.
Implementation · Refactoring
Regular expressions can become error prone when defining a complex language even for those experienced in writing grammars. Determine if several smaller regular expressions simplify one large regular expression.
Attack patterns
Command Delimiters (opens in a new tab)
Argument Injection (opens in a new tab)
Using Slashes in Alternate Encoding (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 23 May 2026, 06:15 UTC

WeaknessesCWE-185

Technical details

References

Community reviews

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