CVE-2026-48791VulnerabilityPublished 30 Jun 2026

Dev.sigstore:sigstore java: Sigstore Java has a vulnerability with bundle verification of integratedTime

Affects dev.sigstore:sigstore-javaSource GCVE Database

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Authoritative record:CVE-2026-48791· Low 2.0

Not known to be exploited · CVSS 2.0 Low : upgrade to 2.1.0 when convenient.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

2.0Low

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

EPSS: 0.07% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.1.0

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: High
User Interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
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: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 12 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CISA SSVC: proof of concept public
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

CVE ID reserved
by GitHub, Inc.
22 May 202620:18 UTC, 82 days before disclosure
CVE published
on cve.org
12 Aug 202623:42 UTC, t = 0
CISA SSVC assessment
proof of concept public
13 Aug 202613:06 UTC, 13 hours after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, 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 dev.sigstore:sigstore-java to 2.1.0.

Affected software

Product	Affected	Fixed in
Mavendev.sigstore:sigstore-java	Affected >=2.0.0 <2.1.0 =2.0.0	Fixed in 2.1.0

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

Description

### Summary Regression: Verification of `integratedTime` from Rekor V1 Log Entry against Fuclio Certificate validity was missing ### Details - PR [#1008](https://github.com/sigstore/sigstore-java/pull/1008) erroneously removed verification of the integrated (Rekor entry) time) against the Fulcio certificate. - PR [#1185](https://github.com/sigstore/sigstore-java/pull/1185) re-added this verification with enhancements that adhere to the Sigstore verification spec. - old sigstore-conformance test for this check was built incorrectly ### PoC A new bundle was added to sigstore-conformance to test this: sigstore-java:2.0.0 can be tested against it and shown to be unexpectedly passing Verify this [bundle](https://github.com/aaronlew02/sigstore-conformance/blob/8b45823fd0d82236ff42aea5b06c98d5109a0e6d/test/assets/bundle-verify/integrated-time-in-future_fail/bundle.sigstore.json) against [`a.txt`](https://github.com/aaronlew02/sigstore-conformance/blob/8b45823fd0d82236ff42aea5b06c98d5109a0e6d/test/assets/a.txt) ``` $ git clone git@github.com:sigstore/sigstore-java $ git checkout v2.0.0 $ ./gradlew :sigstore-cli:build $ tar -xf sigstore-cli/build/distributions/sigstore-cli-*-SNAPSHOT.tar --strip-components 1 $ ./bin/sigstore-cli verify --bundle=bundle.sigstore.json a.txt # expect error but none ``` ### Impact This vulnerability impacts only users verifying bundles with `dev.sigstore:sigstore-java:2.0.0`. Older versions are not affected, it is fixed in `dev.sigstore:sigstore-java:2.1.0` A malicious actor may exploit this if they were able to access a users system and exfiltrate the temporary private key used during signing and then reuse an old fulcio certificate later without requiring direct access to the user's credentials. Users may protect themselves by re-verifying their artifacts using the newest sigstore-java or another current sigstore client. Transparency logs may also be audited for unauthorized signatures for a suspected reused identity.

CWE-347Improper Verification of Cryptographic Signature (opens in a new tab)
Base weaknessOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
OWASP Cheat Sheets
XML Security (opens in a new tab)
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
REST Assessment (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.2 (opens in a new tab)
V3.5.3 (opens in a new tab)
V13.2.6 (opens in a new tab)
Attack patterns
Padding Oracle Crypto Attack (opens in a new tab)
Signature Spoofing by Improper Validation (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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What to do

Affected software

Description

WeaknessesCWE-347

Technical details

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