How severe is CVE-2026-123608?

No CVSS score has been assigned to CVE-2026-123608 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-123608?

CVE-2026-123608 affects the following packages: hickory-proto (crates.io). Ecosystems affected: crates.io.

How do I fix CVE-2026-123608?

Update hickory-proto to 0.26.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-123608 is resolved across your whole dependency graph.

How do I detect CVE-2026-123608 in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hickory-proto, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-123608 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2026-123608 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-123608 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-123608?

CVE-2026-123608 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 35th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-123608?

CVE-2026-123608 is classified as CWE-407 (CWE-407). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-123608 published, and has it been updated?

CVE-2026-123608 was published on November 8, 2026 and was last updated on November 9, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🦀 crates.io

Not in CISA KEV

CVE-2026-123608 — hickory-proto

CVE-2026-123608 is a CWE-407 vulnerability in hickory-proto. A fix is available for hickory-proto — see the affected versions and patch details below.

Hickory DNS hickory-proto 0.3.1 before 0.26.1 CPU Exhaustion via BinEncoder Name Compression

Also known asGHSA-q2qq-hmj6-3wppRUSTSEC-2026-0119

Published

Nov 8, 2026

Updated

Nov 9, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs35th percentile — riskier than 35% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🦀hickory-proto

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.

Description

During message encoding, hickory-proto's BinEncoder stores pointers to labels that are candidates for name compression in a Vec<(usize, Vec<u8>)>. The name compression logic then searches for matches with a linear scan.

A malicious message with many records can both introduce many candidate labels, and invoke this linear scan many times. This can amplify CPU exhaustion in DoS attacks.

This is similar to CVE-2024-8508.

Reporter

Qifan Zhang, Palo Alto Networks

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`hickory-proto`	≥ 0.3.1&&< 0.26.1	0.26.1`cargo update -p hickory-proto --precise 0.26.1`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hickory-proto, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update hickory-proto to 0.26.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-123608 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

During message encoding, `hickory-proto`'s `BinEncoder` stores pointers to labels that are candidates for name compression in a `Vec<(usize, Vec<u8>)>`. The name compression logic then searches for matches with a linear scan. A malicious message with many records can both introduce many candidate labels, and invoke this linear scan many times. This can amplify CPU exhaustion in DoS attacks. This is similar to [CVE-2024-8508](https://www.nlnetlabs.nl/downloads/unbound/CVE-2024-8508.txt). ### Reporter Qifan Zhang, Palo Alto Networks

O3 Security · Impact-Aware SCA

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