CVE-2025-67897: Sequoia openpgp Sequoia PGP Has Subtraction Overflow Vulnerability

MODERATE
Advisory Identifier: GHSA-v6x3-9r38-r27q
CVSS 5.3
CWE-195
Published
Advisory Summary

CVE-2025-67897 is a MODERATE (CVSS 5.3) sequoia pgp has subtraction overflow vulnerability (CWE-195: Signed to Unsigned Conversion Error) affecting Sequoia openpgp libraries in the crates.io ecosystem. The issue involves sequoia pgp has subtraction overflow when aes_key_unwrap function is provided ciphertext that is too short. Remediation is available by upgrading affected packages to version 2.1.0.

CVE-2025-67897 at a Glance

CVE Identifier CVE-2025-67897
GHSA Identifier GHSA-v6x3-9r38-r27q
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-195: Signed to Unsigned Conversion Error
Affected Product Sequoia openpgp
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 5.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2025-67897

To remediate this vulnerability, upgrade all affected Sequoia openpgp dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

sequoia-openpgp fixed: 2.1.0
Upgrade sequoia-openpgp to 2.1.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for sequoia-openpgp

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-67897, inspect your project dependencies for Sequoia openpgp:

inspect dependencies for sequoia-openpgp

Analyze the terminal output to locate any version of Sequoia openpgp in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.1.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-195: Signed to Unsigned Conversion Error, where the product uses a signed primitive and performs a cast to an unsigned primitive, which can produce an unexpected value if the value of the signed primitive can not be represented using an unsigned primitive. In Sequoia openpgp, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

In Sequoia before 2.1.0, aes_key_unwrap panics if passed a ciphertext that is too short. A remote attacker can take advantage of this issue to crash an application by sending a victim an encrypted message with a crafted PKESK or SKESK packet.

CVE-2025-67897 Affected Sequoia openpgp Versions

1 component(s)
Fixed Versions:
2.1.0
Product / Package Ecosystem Affected Versions Fixed Version
sequoia-openpgp
crates.io
< 2.1.0
2.1.0

References

Frequently Asked Questions

What is CVE-2025-67897?
CVE-2025-67897 is a security vulnerability in Sequoia openpgp involving Sequoia PGP has Subtraction Overflow when aes_key_unwrap function is provided ciphertext that is too short under CWE-195: Signed to Unsigned Conversion Error.
Which Sequoia openpgp versions are affected?
Affected versions include releases prior to 2.1.0 across affected packages: sequoia-openpgp.
What version fixes CVE-2025-67897?
Upgrading to 2.1.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is sequoia-openpgp affected?
Yes, sequoia-openpgp is affected in releases prior to 2.1.0. Upgrade your dependency to 2.1.0 or later.
What is the CVSS score of CVE-2025-67897?
CVE-2025-67897 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2025-67897?
CVE-2025-67897 is classified under CWE-195: Signed to Unsigned Conversion Error (The product uses a signed primitive and performs a cast to an unsigned primitive, which can produce an unexpected value if the value of the signed primitive can not be represented using an unsigned primitive.).
How can I check crates.io dependencies for CVE-2025-67897?
Run the dependency tree command: 'inspect dependencies for sequoia-openpgp'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-v6x3-9r38-r27q",
  "modified" : "2025-12-16T19:30:41Z",
  "published" : "2025-12-14T06:30:24Z",
  "aliases" : [ "CVE-2025-67897" ],
  "summary" : "Sequoia PGP has Subtraction Overflow when aes_key_unwrap function is provided ciphertext that is too short",
  "details" : "In Sequoia before 2.1.0, aes_key_unwrap panics if passed a ciphertext that is too short. A remote attacker can take advantage of this issue to crash an application by sending a victim an encrypted message with a crafted PKESK or SKESK packet.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "sequoia-openpgp"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.1.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-67897"
  }, {
    "type" : "WEB",
    "url" : "https://bugs.debian.org/1122582"
  }, {
    "type" : "PACKAGE",
    "url" : "https://gitlab.com/sequoia-pgp/sequoia"
  }, {
    "type" : "WEB",
    "url" : "https://gitlab.com/sequoia-pgp/sequoia/-/blob/b59886e5e7bdf7169ed330f309a6633d131776e5/openpgp/NEWS#L7-L26"
  }, {
    "type" : "WEB",
    "url" : "https://gitlab.com/sequoia-pgp/sequoia/-/commit/b59886e5e7bdf7169ed330f309a6633d131776e5"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2025-0136.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-195" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-12-16T19:30:41Z",
    "nvd_published_at" : "2025-12-14T05:16:06Z"
  }
}