CVE-2025-59530: quic-go Panic Occurs When Queuing Undecryptable Vulnerability

HIGH
Advisory Identifier: GHSA-47m2-4cr7-mhcw
CVSS 7.5
CWE-617 CWE-755
Published
Advisory Summary

CVE-2025-59530 is a HIGH (CVSS 7.5) panic occurs when queuing undecryptable vulnerability (CWE-617: Reachable Assertion) affecting quic-go libraries in the Go ecosystem. The issue involves panic occurs when queuing undecryptable packets after handshake completion. Remediation is available by upgrading affected packages to version 0.49.1, 0.54.1.

CVE-2025-59530 at a Glance

CVE Identifier CVE-2025-59530
GHSA Identifier GHSA-47m2-4cr7-mhcw
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-617: Reachable Assertion
Affected Product quic-go
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 7.5

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

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

How to Fix CVE-2025-59530

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

github.com/quic-go/quic-go fixed: 0.49.1
Upgrade github.com/quic-go/quic-go to 0.49.1
github.com/quic-go/quic-go fixed: 0.54.1
Upgrade github.com/quic-go/quic-go to 0.54.1
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 github.com/quic-go/quic-go

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-59530, inspect your project dependencies for quic-go:

inspect dependencies for github.com/quic-go/quic-go

Analyze the terminal output to locate any version of quic-go in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.49.1), 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-617: Reachable Assertion, where the product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary. In quic-go, 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

## Summary A misbehaving or malicious server can trigger an assertion in a quic-go client (and crash the process) by sending a premature HANDSHAKE_DONE frame during the handshake. ## Impact A misbehaving or malicious server can cause a denial-of-service (DoS) attack on the quic-go client by triggering an assertion failure, leading to a process crash. This requires no authentication and can be exploited during the handshake phase. Observed in the wild with certain server implementations (e.g. Solana's Firedancer QUIC). ## Affected Versions - All versions prior to v0.49.1 (for the 0.49 branch) - Versions v0.50.0 to v0.54.0 (inclusive) - Fixed in v0.49.1, v0.54.1, and v0.55.0 onward Users are recommended to upgrade to the latest patched version in their respective maintenance branch or to v0.55.0 or later. ## Details For a regular 1-RTT handshake, QUIC uses three sets of keys to encrypt / decrypt QUIC packets: - Initial keys (derived from a static key and the connection ID) - Handshake keys (derived from the client's and server's key shares in the TLS handshake) - 1-RTT keys (derived when the TLS handshake finishes) On the client side, Initial keys are discarded when the first Handshake packet is sent. Handshake keys are discarded when the server's HANDSHAKE_DONE frame is received, as specified in section 4.9.2 of RFC 9001. Crucially, Initial keys are always dropped before Handshake keys in a standard handshake. Due to packet reordering, it is possible to receive a packet with a higher encryption level before the key for that encryption level has been derived. For example, the server's Handshake packets (containing, among others, the TLS certificate) might arrive before the server's Initial packet (which contains the TLS ServerHello). In that case, the client queues the Handshake packets and decrypts them as soon as it has processed the ServerHello and derived Handshake keys. After completion of the handshake, Initial and Handshake packets are not needed anymore and will be dropped. quic-go implements an [assertion](https://github.com/quic-go/quic-go/blob/v0.55.0/connection.go#L2682-L2685) that no packets are queued after completion of the handshake. A misbehaving or malicious server can trigger this assertion, and thereby cause a panic, by sending a HANDSHAKE_DONE frame before actually completing the handshake. In that case, Handshake keys would be dropped before Initial keys. This can only happen if the server implementation is misbehaving: the server can only complete the handshake after receiving the client's TLS Finished message (which is sent in Handshake packets). ## The Fix quic-go needs to be able to handle misbehaving server implementations, including those that prematurely send a HANDSHAKE_DONE frame. We now discard Initial keys when receiving a HANDSHAKE_DONE frame, thereby correctly handling premature HANDSHAKE_DONE frames. The fix was implemented in https://github.com/quic-go/quic-go/pull/5354.

CVE-2025-59530 Affected quic-go Versions

2 component(s)
Fixed Versions:
0.49.10.54.1
Product / Package Ecosystem Affected Versions Fixed Version
github.com/quic-go/quic-go
Go
< 0.49.1
0.49.1
github.com/quic-go/quic-go
Go
≥ 0.50.0
< 0.54.1
0.54.1

References

Frequently Asked Questions

What is CVE-2025-59530?
CVE-2025-59530 is a security vulnerability in quic-go involving Panic occurs when queuing undecryptable packets after handshake completion under CWE-617: Reachable Assertion.
Which quic-go versions are affected?
Affected versions include releases prior to 0.49.1, 0.54.1 across affected packages: github.com/quic-go/quic-go.
What version fixes CVE-2025-59530?
Upgrading to 0.49.1, 0.54.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/quic-go/quic-go affected?
Yes, github.com/quic-go/quic-go is affected in releases prior to 0.49.1, 0.54.1. Upgrade your dependency to 0.49.1, 0.54.1 or later.
What is the CVSS score of CVE-2025-59530?
CVE-2025-59530 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2025-59530?
CVE-2025-59530 is classified under CWE-617: Reachable Assertion (The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.).
How can I check Go dependencies for CVE-2025-59530?
Run the dependency tree command: 'inspect dependencies for github.com/quic-go/quic-go'. 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-47m2-4cr7-mhcw",
  "modified" : "2025-11-05T22:06:25Z",
  "published" : "2025-10-10T17:03:01Z",
  "aliases" : [ "CVE-2025-59530" ],
  "summary" : "quic-go: Panic occurs when queuing undecryptable packets after handshake completion",
  "details" : "## Summary\n\nA misbehaving or malicious server can trigger an assertion in a quic-go client (and crash the process) by sending a premature HANDSHAKE_DONE frame during the handshake.\n\n## Impact\n\nA misbehaving or malicious server can cause a denial-of-service (DoS) attack on the quic-go client by triggering an assertion failure, leading to a process crash. This requires no authentication and can be exploited during the handshake phase. Observed in the wild with certain server implementations (e.g. Solana's Firedancer QUIC).\n\n## Affected Versions\n\n- All versions prior to v0.49.1 (for the 0.49 branch)\n- Versions v0.50.0 to v0.54.0 (inclusive)\n- Fixed in v0.49.1, v0.54.1, and v0.55.0 onward\n\nUsers are recommended to upgrade to the latest patched version in their respective maintenance branch or to v0.55.0 or later.\n\n## Details\n\nFor a regular 1-RTT handshake, QUIC uses three sets of keys to encrypt / decrypt QUIC packets:\n\n- Initial keys (derived from a static key and the connection ID)\n- Handshake keys (derived from the client's and server's key shares in the TLS handshake)\n- 1-RTT keys (derived when the TLS handshake finishes)\n\nOn the client side, Initial keys are discarded when the first Handshake packet is sent. Handshake keys are discarded when the server's HANDSHAKE_DONE frame is received, as specified in section 4.9.2 of RFC 9001. Crucially, Initial keys are always dropped before Handshake keys in a standard handshake.\n\nDue to packet reordering, it is possible to receive a packet with a higher encryption level before the key for that encryption level has been derived. For example, the server's Handshake packets (containing, among others, the TLS certificate) might arrive before the server's Initial packet (which contains the TLS ServerHello). In that case, the client queues the Handshake packets and decrypts them as soon as it has processed the ServerHello and derived Handshake keys.\n\nAfter completion of the handshake, Initial and Handshake packets are not needed anymore and will be dropped. quic-go implements an [assertion](https://github.com/quic-go/quic-go/blob/v0.55.0/connection.go#L2682-L2685) that no packets are queued after completion of the handshake.\n\nA misbehaving or malicious server can trigger this assertion, and thereby cause a panic, by sending a HANDSHAKE_DONE frame before actually completing the handshake. In that case, Handshake keys would be dropped before Initial keys.\n\nThis can only happen if the server implementation is misbehaving: the server can only complete the handshake after receiving the client's TLS Finished message (which is sent in Handshake packets).\n\n## The Fix\n\nquic-go needs to be able to handle misbehaving server implementations, including those that prematurely send a HANDSHAKE_DONE frame. We now discard Initial keys when receiving a HANDSHAKE_DONE frame, thereby correctly handling premature HANDSHAKE_DONE frames. The fix was implemented in https://github.com/quic-go/quic-go/pull/5354.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/quic-go/quic-go"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.49.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/quic-go/quic-go"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.50.0"
      }, {
        "fixed" : "0.54.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/quic-go/quic-go/security/advisories/GHSA-47m2-4cr7-mhcw"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-59530"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/quic-go/quic-go/pull/5354"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/quic-go/quic-go/commit/bc5bccf10fd02728eef150683eb4dfaa5c0e749c"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/quic-go/quic-go/commit/ce7c9ea8834b9d2ed79efa9269467f02c0895d42"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/quic-go/quic-go"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/quic-go/quic-go/blob/v0.55.0/connection.go#L2682-L2685"
  }, {
    "type" : "WEB",
    "url" : "https://pkg.go.dev/vuln/GO-2025-4017"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-617", "CWE-755" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-10-10T17:03:01Z",
    "nvd_published_at" : "2025-10-10T16:15:52Z"
  }
}