Code Signing Certificate Validity Reduced to 460 Days: What’s Changing in 2026?

Breaking Down the Shorter Code Signing Validity Update

For years, code signing certificates were issued with multi-year validity up to 3 years – often long enough to outlive internal ownership changes, tooling upgrades, and even the teams responsible for them.

Beginning March 1, 2026, publicly trusted code signing certificates will be limited to a maximum validity of 460 days (~15 months), under updated CA/Browser Forum Code Signing Baseline Requirements.

This reflects a deeper shift in how the industry now views software identity, key risk, and long-term trust.

What Changes – and What Doesn’t – Under the 460-day Limit

Starting in 2026, any newly issued or renewed publicly trusted code signing certificate must not exceed 460 days of validity. Certificates issued before the enforcement date are unaffected and will continue to function until their natural expiration.

What’s important is what does not change:

• The cryptographic signing process remains the same
• Existing signing tools and verification logic continue to work
• Timestamped software remains trusted after certificate expiration
• Operating systems do not re-evaluate old signatures retroactively

If code was signed while the certificate was valid and properly timestamped, that signature continues to be trusted even after the certificate expires. That trust model already exists and stays exactly the same.

The only thing being shortened is how long a single certificate can exist before the publisher has to re-establish trust.

This change is forward-looking. It alters how future trust credentials are issued and not how existing signed software is interpreted.

Why Long-lived Code Signing Certificates No Longer Hold Up

Code signing certificates bind publisher identity to a private signing key. If that key is compromised, attackers can distribute malware that appears legitimate, often bypassing reputation systems and security prompts entirely.

The problem with long validity periods is not theoretical. Real-world attacks have shown that:

• Key compromise often goes undetected for months
• CI/CD pipelines are increasingly targeted
• Stolen certificates retain value for as long as they remain valid

Today, a compromised code signing key can sit undetected while malware is signed, distributed, and trusted by systems that are explicitly designed to block unknown publishers. The longer that certificate remains valid, the more valuable it becomes to an attacker.

A three-year certificate creates a long, quiet abuse window. By reducing validity to 15 months, the industry is shrinking that window dramatically. Even if a compromise occurs, its impact is inherently time-limited. This approach prioritizes risk containment by sharply reducing the lifespan of compromised credentials.

How Trust Survives Certificate Expiry in Code Signing

In practice, trust in code signing has never depended on how long a certificate lasts, it depends on when the code was signed.

Trust is established through three technical conditions:

1. The certificate was valid at signing time
2. The binary has not been altered
3. A trusted timestamp proves when signing occurred

When these conditions are met, signed software remains trusted indefinitely, even after the certificate expires. The 460-day limit does not invalidate existing software, nor does it break long-term distribution models.

What it does is prevent stale credentials from remaining silently authoritative for years.

Supply Chain Security is the Real Driver

Modern software attacks rarely break cryptography. They exploit trust assumptions.

Attackers target signing keys because a valid signature lets malicious code blend in. Long-lived certificates make that strategy profitable. Shorter lifetimes reduce the incentive and the scale of potential abuse.

From a supply chain perspective, the 460-day limit:

• Narrows the usefulness of stolen credentials
• Makes revocation more meaningful
• Forces identity to be re-validated more frequently

This aligns code signing with broader security principles already applied across PKI: minimize standing trust, rotate credentials, and assume compromise is possible.

What Changes for Developers and Release Teams?

For developers, nothing changes in how code is signed. The impact is operational, not procedural.

Certificates will expire more often. That means:

• Renewals happen more frequently
• Ownership of signing identities must be explicit
• Build pipelines must tolerate certificate rotation

Teams relying on calendar reminders, shared inboxes, or manual procurement will feel friction quickly. Missed renewals can block releases, delay patches, or force emergency workarounds.

The change exposes a simple reality: manual certificate management does not scale.

As certificate lifecycles shorten, teams are paying closer attention to how different code signing certificates fit into their release and trust models.

Best Code Signing Certificate Options

Why Timestamping Becomes Non-negotiable Under Shorter Validity Periods?

As validity windows shrink, timestamping moves from “best practice” to “foundational requirement.”

Without proper timestamping:

• Signed software can lose trust after certificate expiration
• Long-term distribution breaks
• Release artifacts become fragile

With correct timestamping:

• Software remains trusted indefinitely
• Certificate expiration becomes operational, not existential

Organizations that have treated timestamping casually will need to revisit their workflows.

Automation is No Longer Optional

The 460-day limit does not mandate automation – but it strongly favors it.

Frequent renewals combined with fast release cycles create failure points when humans are in the loop. Automation turns certificate lifecycle management into infrastructure:

• Predictable renewals
• No last-minute scrambling
• No broken builds due to expired credentials

This mirrors the evolution already seen in SSL/TLS. Code signing is simply catching up.

Preparing for the 460-day Code Signing Certificate Era

Waiting until 2026 means reacting under pressure. Preparing now allows gradual adaptation.

Practical preparation starts with visibility:

• Identify all active code signing certificates
• Map where they are used
• Assign ownership clearly

From there, teams can assess whether their signing infrastructure supports shorter lifecycles without disrupting delivery.

Is 460 Days the Final State?

Probably not. Public PKI has consistently moved toward shorter-lived credentials as automation and maturity increase. Each reduction reflects growing expectations around accountability, automation, and security responsiveness. Code signing is now on that same trajectory.

The shift to 460 days should be seen as a checkpoint, not a finish line. Software trust is evolving toward models that favor continuous validation over long-term assumptions. Organizations that adapt early will find future changes incremental rather than disruptive.

Final Perspective

The reduction of code signing certificate validity to 460 days is not about tightening rules. It reflects a modern understanding of risk and how software trust is managed – away from long-term assumptions and toward continuous validation.

For developers and publishers, the change rewards disciplined lifecycle management and forward-looking infrastructure. For the ecosystem as a whole, it strengthens trust. The change isn’t disruptive but long overdue.

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