CVE 2026 Half-Year Forecast Update

How the FIRST.org February Forecast Is Holding Up Against Reality
Data through April 30, 2026 • Source: CVE Program (cvelistV5) • Jerry Gamblin • May 5, 2026
+46.3%
Cumulative Drift
(Jan to Apr 2026)
30.6%
MAPE
(Forecast Error Rate)
+6,420
Excess CVEs
Above February Forecast
65,632
Revised 2026 Total
(was 43,757)

The Short Version

In February 2026, FIRST.org published its annual vulnerability forecast predicting roughly 43,757 CVEs would be published this year. Four months later, that number is already wrong by a wide margin. Actual publications are running 46% above the forecast, and the gap is widening.

This is not because software suddenly became less secure. The overshoot is almost entirely explained by two organizations dramatically scaling their CVE assignment operations: GitHub Security Advisories (GHSA) and VulnCheck. Together they added over 4,300 CVEs that the February model never anticipated.

The deeper question is whether this volume surge matters for defenders. Our analysis of CISA KEV and EPSS data shows that it largely does not. Less than 1% of the new volume from these CNAs meets a reasonable threshold for immediate action. Volume is not burden.

This page presents the full data, the revised forecast, and an exploitability overlay that separates signal from noise. All code and data are available in the GitHub repository.

What the Daily Data Looks Like

The chart below shows every CVE published between January 1 and April 30, 2026. The raw daily counts (light line) are noisy due to weekend dips and batch-publication spikes, so the bold line shows a 7-day moving average to reveal the true trend. Three days stand out as statistical outliers, each driven by coordinated batch publications from multiple CNAs.

Date CVEs Z-Score What Happened
March 25 (Tue) 619 +3.81 Patchstack (248) + Linux kernel (116) + Apple (87) published simultaneously
March 5 (Wed) 490 +2.72 Patchstack WordPress plugin batch (268) + VulnCheck (49)
April 8 (Tue) 485 +2.68 Patchstack (164) + GHSA (69) + Chrome stable channel update (60)

All three outlier days fall on Tuesday or Wednesday, consistent with 42.8% of all CVE publications occurring on these two days. CNA operations clearly run on business-day schedules.

Month by Month: Forecast vs. Reality

The divergence did not appear all at once. January came in 28% above forecast, which could have been normal variance. But the gap widened to 62% in March before stabilizing at 59% in April. This acceleration pattern points to a structural shift rather than random noise. The February model was trained on 2024 to 2025 behavior, and it simply could not account for the CNA operational expansions that began in late 2025.

Month Actual Feb Forecast Delta % Over
January 2026 4,283 3,338 +945 +28.3%
February 2026 4,420 3,320 +1,100 +33.1%
March 2026 5,930 3,651 +2,279 +62.4%
April 2026 5,660 3,564 +2,096 +58.8%
Total (Jan to Apr) 20,293 13,873 +6,420 +46.3%

Who Is Driving the Growth

Two CNAs account for most of the overshoot. GitHub Security Advisories (GHSA, published under the CNA shortName "GitHub_M") grew from 785 CVEs in Jan to Apr 2025 to 4,313 in the same period this year, a 449% increase. This reflects an expanded curation team and a deliberate campaign to backfill CVE IDs for advisories that previously existed only as GHSA identifiers. VulnCheck, operating as a CNA of Last Resort that assigns IDs to vulnerabilities no other CNA has claimed, scaled from 26 CVEs to 837 (+3,119%).

On the decline side, Patchstack dropped 43% and MITRE fell 29%. But the net math is clear: the growers outweigh the shrinkers by a wide margin.

CNA 2025 2026 Change YoY Context
GitHub_M (GHSA) 785 4,313 +3,528 +449% Scaled Ops Backfilling CVE IDs for existing GHSA-only advisories
VulnCheck 26 837 +811 +3,119%* Last Resort Assigning IDs to previously unowned vulnerabilities
VulDB 1,419 2,210 +791 +56% Steady growth in community-sourced disclosures
Linux 804 1,022 +218 +27% Kernel CNA continues steady growth
Chrome 52 252 +200 +385%* Increased Chromium/V8 disclosure cadence
Mozilla 73 176 +103 +141% AI Discovery Project Glasswing collaboration with Anthropic (Q1-only: +164%)
Patchstack 3,219 1,828 -1,391 -43% Reduced WordPress plugin disclosure volume down significantly
MITRE 1,823 1,293 -530 -29% Declining as 400+ product-specific CNAs assign their own IDs

* Small-base percentages (VulnCheck from 26, Chrome from 52) are visually dramatic but reflect a single quarter's ramp from near-zero. These growth rates will not persist at this magnitude.

The important framing: GHSA's +3,528 CVEs alone account for more than half of all year-over-year growth. This is a cataloging expansion, meaning increased visibility into existing open-source vulnerabilities, not evidence that open-source software suddenly became less secure. The growth should plateau as the backfill of existing GHSA-only advisories completes.
The AI angle: Mozilla's 141% increase (Jan–Apr YoY) is partly driven by Project Glasswing, a joint Mozilla and Anthropic initiative applying large language models to systematic codebase auditing. Anthropic's models autonomously discovered 22 vulnerabilities patched in Firefox 148, and a newer variant found 271 legacy bugs patched in Firefox 150. VulnCheck has tracked 40 CVEs credited to Anthropic researchers so far in 2026. AI-discovered CVEs remain less than 1% of total volume, but the trajectory suggests AI-assisted auditing will become structurally significant in H2 2026 and beyond.

The Revised Forecast

We retrained an ExponentialSmoothing model on the full daily time series from January 2020 through April 30, 2026 and projected forward through December. The revised model projects 65,632 total CVEs for 2026, compared to FIRST.org's original 43,757. That is a 50% upward revision.

A few caveats are important. This model assumes the current publication regime persists. If GHSA's backfill campaign saturates or VulnCheck's pipeline plateaus, actual volumes could come in materially lower. The monthly projections below reflect an ExponentialSmoothing model (AutoARIMA was unavailable on the analysis platform); real months will be more volatile.

Month Revised Feb Forecast Delta
May 2026 5,326 3,782 +1,544
June 2026 5,498 3,655 +1,843
July 2026 5,761 3,821 +1,940
August 2026 5,499 3,750 +1,749
September 2026 5,736 3,690 +2,046
October 2026 5,784 3,790 +1,994
November 2026 5,593 3,520 +2,073
December 2026 6,143 3,876 +2,267
Full Year 2026 65,632 43,757 +21,875 (+50%)

Historical Context

If the revised projection holds, 2026 will see the fastest growth in CVE publication history. The ecosystem crossed 1,000 published CVEs per week for the first time in March 2026 and has not dropped below that pace since. For context: in 2020, the full year produced 14,287 CVEs. We are now on track to exceed that in a single quarter.

Does Volume Equal Burden?

The headline numbers are alarming, but they raise an important follow-up question: does this volume growth actually translate into more work for defenders? To find out, we enriched every CVE published by GitHub_M and VulnCheck with two exploitability signals. A CVE is classified as "Actionable" if it appears in the CISA Known Exploited Vulnerabilities (KEV) catalog or has an EPSS score above 10%. We then trained separate AutoARIMA models on the total volume and the actionable subset, forecasting both through December 2026.

The answer is clear: the growth is almost entirely non-actionable.

Exploitability Overlay: Forecasted Volume vs. Actionable Burden

7-day rolling average. Dashed lines represent forecasted total volume. Solid lines represent forecasted actionable volume. Shaded region is the non-actionable gap. AutoARIMA models trained on daily counts from 2020 through April 2026.

GitHub_M
Forecasted Total (May to Dec) 7,773
Forecasted Actionable 47
Actionable Ratio 0.6%
Non-Actionable 99.4%
VulnCheck
Forecasted Total (May to Dec) 3,027
Forecasted Actionable 22
Actionable Ratio 0.7%
Non-Actionable 99.3%
Bottom line: GitHub Security Advisories is forecasted to publish 7,773 CVEs in the May through December window, but only 0.6% meet the threshold for immediate prioritization. VulnCheck's projected 3,027 CVEs yield just 0.7% actionable entries. The overwhelming majority of volume growth represents low-severity ecosystem advisories that are valuable for dependency tracking but do not indicate active exploitation risk. Volume does not equal burden.

What This Means for Vulnerability Management Teams

The February 2026 forecast no longer reflects current CNA dynamics and requires revision. It was calibrated against 2024 to 2025 behavior that has since been superseded by structural shifts in how CVEs are assigned. Here is what practitioners should take away:

Plan for 5,800 to 6,200 new CVEs per month for the remainder of 2026, but recognize that raw volume alone is a poor proxy for risk. Prioritization should lean heavily on exploitability signals (EPSS scores, CISA KEV membership) and affected-product relevance rather than CVE count.

Filter by CNA source when triaging. A GHSA advisory for a transitive npm dependency carries different operational urgency than a Chrome or Linux kernel CVE. Not all CVEs deserve the same SLA.

Monitor NVD enrichment lag. Teams relying on NVD-enriched data should verify whether NVD analysis throughput is keeping pace with this publication volume. Enrichment lag creates blind spots where CVEs exist in the catalog but lack CVSS scores or CPE data.

This is not a vulnerability explosion. The underlying rate of software defects has not increased 46% in four months. The CVE catalog is expanding its coverage, particularly for open-source library vulnerabilities that previously went untracked or existed only in platform-specific databases. Whether this represents the CVE system catching up to reality or a dilution of signal quality is a matter of ongoing debate within the CNA community.

Appendix: Publication Cadence

Patterns in Jan to Apr 2026:

  • Tuesday and Wednesday: 42.8% of all publications
  • Weekends: only 8.1% (CNA ops are business-day)
  • Weekly average: 1,085 CVEs/week (std: 346)
  • Peak week: 1,608 CVEs
  • The "Patch Tuesday" effect is clearly visible

Methodology and Limitations

This analysis uses the datePublished field from CVE V5 JSON records in the cvelistV5 repository, which reflects when a CVE was published to the catalog rather than when the vulnerability was discovered or disclosed. Some of the observed growth, particularly from GHSA and VulnCheck, includes backfill of previously known vulnerabilities now receiving CVE IDs for the first time. The true rate of newly discovered vulnerabilities is growing more slowly than these publication counts suggest.

The forecast model is ExponentialSmoothing (via Darts) trained on daily CVE counts from January 1, 2020 through April 30, 2026. AutoARIMA was the intended model but is unavailable on Python 3.14 (no statsforecast wheel). The exploitability overlay uses CISA KEV (1,587 entries, filtered to ≤ May 1 2026) and EPSS scores (329,934 CVEs scored) from the May 1, 2026 daily snapshot.

All source code, data processing scripts, and analysis are available at github.com/jgamblin/FirstForecast.