CVE-2025-59530

highpriority · track · 0EPSS 0.005 · 39 %ileDEEUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.46% (39th) EPSS
CVSS 7.5 · high
Is it mine?
10 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · osv · cert_bund

EPSS · scored 2026-10-22

quic-go is an implementation of the QUIC protocol in Go. In versions prior to 0.49.0, 0.54.1, and 0.55.0, 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. This was observed in the wild with certain server implementations. quic-go needs to be able to handle misbehaving server implementations, including those that prematurely send a HANDSHAKE_DONE frame. Versions 0.49.0, 0.54.1, and 0.55.0 discard Initial keys when receiving a HANDSHAKE_DONE frame, thereby correctly handling premature HANDSHAKE_DONE frames.

01

cvss

Technical severity, 0–10. One row per scoring source.

7.5
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · ENISA EU
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · security-advisories@github.comexploitability 3.9 · impact 3.6
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · OSV
v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

04

affected products (10)

Products and version ranges known to be affected.

05

advisories (3)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2025-2635Red Hat Ansible Automation Platform: Schwachstelle ermöglicht Denial of ServiceDeutsch2025-11-18csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Red Hat Ansible Automation Platform ausnutzen, um einen Denial of Service Angriff durchzuführen.

  • GHSA-47m2-4cr7-mhcwquic-go: Panic occurs when queuing undecryptable packets after handshake completion2025-10-10ghsa · osvUS

    ## 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.

  • GO-2025-4017Panic occurs when queuing undecryptable packets after handshake completion in github.com/quic-go/quic-go2025-11-05vendor · osvUS

    Panic occurs when queuing undecryptable packets after handshake completion in github.com/quic-go/quic-go

06

also known as (5)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

published 2025-10-10modified 2026-10-19
08

references (11)

External citations — patches, advisories, analysis.

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