CVE-2026-48816

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreLOW confidence

This medium-severity CVE scores 6.5 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: cna:github_m
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: —CVSS: 6.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

sigstore-js has Insufficient Verification of Data Authenticity

sigstore-js derives a transparency-log timestamp from tlogEntries[].integratedTime and uses it to validate certificate validity windows and satisfy timestampThreshold. For bundle v0.2, a tlog entry can be inclusionProof-only (no signed inclusionPromise/set), and the inclusion proof path does not cryptographically bind integratedTime. As a result, an attacker who can supply an untrusted bundle can influence time-based verification decisions by choosing integratedTime.

impact

If a consumer accepts attacker-provided bundle v0.2 inputs and relies on tlog-derived timestamps for certificate validity checks, verification can be influenced by an unauthenticated timestamp value. This is a trust gap: integratedTime is treated as a trusted observer timestamp under inclusionProof-only mode even though only the signed inclusionPromise/set path binds it.

affected code

  • packages/verify/src/bundle/index.ts (adds a transparency-log timestamp whenever integratedTime != 0)
  • packages/verify/src/timestamp/index.ts (converts integratedTime to a Date)
  • packages/verify/src/verifier.ts (verifies timestamps before verifying tlog inclusion)
  • packages/verify/src/tlog/index.ts + packages/verify/src/tlog/set.ts (only the inclusionPromise/set path binds integratedTime)

proof of concept

The attached poc.zip contains a self-contained harness that reproduces the behavior on the pinned commit and includes both a canonical test and a negative control.

repro: 1) extract poc.zip into a fresh directory and run the make targets:

unzip poc.zip -d poc
cd poc/poc-F-SIG-JS-TLOGTIME-001
make canonical
make control

2) confirm canonical.log includes:

[CALLSITE_HIT]:
[PROOF_MARKER]:

3) confirm control.log includes:

[NC_MARKER]:

suggested fix

Only treat integratedTime as a trusted timestamp when it is cryptographically bound (for example, via a verified signed inclusionPromise/set). For inclusionProof-only entries, do not count integratedTime toward timestampThreshold, and do not use it for certificate validity decisions unless there is another signed time source (for example, an rfc3161 timestamp).

poc.zip PR_DESCRIPTION.md SUBMISSION.md

CVSS v3
6.5
EG Score
6.5(low)
EPSS
—
KEV
Not listed

Published

July 1, 2026

Last Modified

July 1, 2026

Vendor Advisories for CVE-2026-48816(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Data Freshness Timeline

(refreshed 6× in last 7d / 6× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-06 19:49 UTCEG score recompute
  2. 2026-07-05 19:51 UTCEG score recompute
  3. 2026-07-04 19:53 UTCEG score recompute
  4. 2026-07-03 19:56 UTCEG score recompute
  5. 2026-07-02 19:59 UTCEG score recompute
  6. 2026-07-01 20:02 UTCEG score recompute

Frequently asked(4)

What is CVE-2026-48816?
CVE-2026-48816 is a medium vulnerability published on July 1, 2026. sigstore-js has Insufficient Verification of Data Authenticity sigstore-js derives a transparency-log timestamp from tlogEntries[].integratedTime and uses it to validate certificate validity windows and satisfy timestampThreshold. For bundle v0.2, a tlog entry can be inclusionProof-only (no signed…
When was CVE-2026-48816 disclosed?
CVE-2026-48816 was first published in the National Vulnerability Database on July 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-48816?
CVE-2026-48816 has a CVSS v4.0 base score of 6.5 (CNA self-assessment; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-48816?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-48816, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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