CVE-2026-53541

OliveTin has Unvalidated ot_-prefixed Arguments that Bypass Input Filtering

func keepArgument(name string, definedNames map[string]struct{}) bool {
    _, ok := definedNames[name]
    return ok || strings.HasPrefix(name, "ot_")
}

func injectSystemArgs(req *ExecutionRequest) {
    req.Arguments["ot_executionTrackingId"] = req.TrackingID
    req.Arguments["ot_username"] = req.AuthenticatedUser.Username
}

func buildEnv(args map[string]string) []string {
    ret := append(os.Environ(), "OLIVETIN=1")
    for k, v := range args {
        varName := fmt.Sprintf("%v", strings.TrimSpace(strings.ToUpper(k)))
        if varName == "" { continue }
        ret = append(ret, fmt.Sprintf("%v=%v", varName, v))
    }
    return ret
}

{
  "bindingId": "<any-action-id>",
  "arguments": [
    { "name": "ot_custom_var", "value": "arbitrary unvalidated content \n with newlines" },
    { "name": "ot_another",    "value": "$(whoami)" }
  ]
}

• Environment variable pollution, attacker can set arbitrary environment variables (with OT_ uppercased prefix) in the execution environment of any action they can trigger. Scripts or programs that read custom environment variables could be influenced.
• Potential for secondary exploitation, if any executed script or command reads OT_-prefixed environment variables, the unvalidated content could cause unexpected behavior.
• Template context pollution, although Go's text/template does not recursively evaluate data values (mitigating direct template injection), the extra arguments are accessible in the template context and could interact unexpectedly with custom template logic.

The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.

CVE-2026-53541 has a CVSS score of 4.3 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.0.0-20260531214440-ebffd9f040f7); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

Remove the ot_ prefix exception from keepArgument, or restrict it to only the two known system arguments:

var systemArgs = map[string]struct{}{
    "ot_executionTrackingId": {},
    "ot_username":            {},
}

func keepArgument(name string, definedNames map[string]struct{}) bool {
    _, isDefined := definedNames[name]
    _, isSystem := systemArgs[name]
    return isDefined || isSystem
}

1. What is CVE-2026-53541? CVE-2026-53541 is a medium-severity improper input validation vulnerability in github.com/OliveTin/OliveTin (go), affecting versions < 0.0.0-20260531214440-ebffd9f040f7. It is fixed in 0.0.0-20260531214440-ebffd9f040f7. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
2. How severe is CVE-2026-53541? CVE-2026-53541 has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/OliveTin/OliveTin are affected by CVE-2026-53541? github.com/OliveTin/OliveTin (go) versions < 0.0.0-20260531214440-ebffd9f040f7 is affected.
4. Is there a fix for CVE-2026-53541? Yes. CVE-2026-53541 is fixed in 0.0.0-20260531214440-ebffd9f040f7. Upgrade to this version or later.
5. Is CVE-2026-53541 exploitable, and should I be worried? Whether CVE-2026-53541 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-53541 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-53541? Upgrade github.com/OliveTin/OliveTin to 0.0.0-20260531214440-ebffd9f040f7 or later.

Other vulnerabilities in github.com/OliveTin/OliveTin