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No exploitation reportedFix availableAwaiting NVD analysis

CVE-2026-123609

Rustls before 0.23.46 and 0.24.0-dev.1 before 0.24.0-dev.2 Secret Exposure via Debug

No exploitation reported by the sources we read.

  • Published2026-11-08
  • Fixed in0.24.0-dev.2 · 0.23.46
  • WeaknessCWE-212

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Rustls before 0.23.46 and 0.24.0-dev.1 before 0.24.0-dev.2 contains an information disclosure vulnerability where derived Debug formatting of client session values exposes secret key material. Custom ClientSessionStore implementations that log Tls12ClientSessionValue or Tls13ClientSessionValue can leak TLS 1.2 master secrets or TLS 1.3 resumption PSKs to log readers.

Timeline

dates in UTC
  1. 2026-11-0801:38CVE publishedCNA

Versions per branch

OSV
rustls
BranchAffectedFixed in
0.24≥ 0.24.0-dev.1, < 0.24.0-dev.20.24.0-dev.2
0.23< 0.23.460.23.46
0.x≥ 0.21.0, < 0.23.460.23.46

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As VulnCheck, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • rustlsother versions: not affected
    Affected
    • < 0.23.46fixed in 0.23.46semver
    • ≥ 0.24.0-dev.1, < 0.24.0-dev.2fixed in 0.24.0-dev.2semver

    Not affected = 0.23.46 · = 0.24.0-dev.2

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-11-08

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • rust-rustlsDebian:14all versions · no fixed version listed
  • rust-rustlsDebian:13all versions · no fixed version listed
  • rust-rustlsDebian:12all versions · no fixed version listed

Full record on NVD

Fix

  1. Update rustls to 0.24.0-dev.2 · 0.23.46

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Metasploit modules
none listed
Metasploit Framework

Sources

  • CNACVSS 4.04.12026-11-08
  • CNACVSS 3.142026-11-08
  • NVDCVSS 3.14read 2026-11-08
  • CNAweakness (CWE)CWE-2122026-11-08
  • NVDweakness (CWE)CWE-212read 2026-11-08
  • FIRST EPSSEPSS score0.1 %2026-11-08
  • OSVaffected packages—
  • GitHub AdvisoriesadvisoryMODERATE2026-10-27

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N
CVSS 4.0 vector
CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Published
2026-11-08
Last Modified
2026-11-08
NVD status
Received
GitHub Advisory
GHSA-67mj-442h-2gp6 GHSA-c8m5-c952-6cm4

Frequently asked questions

What is CVE-2026-123609?

Rustls before 0.23.46 and 0.24.0-dev.1 before 0.24.0-dev.2 contains an information disclosure vulnerability where derived Debug formatting of client session values exposes secret key material. Custom ClientSessionStore implementations that log Tls12ClientSessionValue or Tls13ClientSessionValue can leak TLS 1.2 master secrets or TLS 1.3 resumption PSKs to log readers.

Is CVE-2026-123609 actively exploited?

Active exploitation of CVE-2026-123609 has not been confirmed. Its EPSS score was 0.1% on 2026-11-08, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-123609?

CVE-2026-123609 has a CVSS v3 base score of 4 (MEDIUM severity), with vector string CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N.

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