CVE Watchtower

CVE-2026-123610rustls rustls Allocation of Resources Without Limits or Throttling

NVD

Vulnerability Summary

rustls before 0.23.46 contains an uncontrolled memory allocation flaw in its optional Brotli certificate decompression, which limits decompressed output size but accepts an input-selected large history window. Malicious peers can send a certificate with a five-byte Brotli header requesting up to 1 GiB before authentication, aborting Brotli-enabled clients or client-authenticating servers whose allocator cannot satisfy the request.
Severity Level
MEDIUM(6.3)
Published Date
Nov 8, 2026
Last Modified
Nov 9, 2026
Exploitation Status
No confirmed exploitation yet
EPSS Score (30-Day)
0.17%Probability
Root Weakness (CWE)
The product allocates a reusable resource on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated.
CVSS v4.0 Base Metrics — Score 6.3 (MEDIUM)
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Attack VectorNetwork
Attack ComplexityHigh
Attack RequirementsPresent
Privileges RequiredNone
User InteractionNone
Confidentiality (Vulnerable System)None
Integrity (Vulnerable System)None
Availability (Vulnerable System)Low
Confidentiality (Subsequent System)None
Integrity (Subsequent System)None
Availability (Subsequent System)None
Show CVSS v3.x metrics (score 3.7)
CVSS v3.1 Base Metrics — Score 3.7 (LOW)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityNone
AvailabilityLow

Affected & Patched Versions

Affected Versions
  • rustls rustls < 0.23.46
Patched Versions
  • rustls rustls 0.23.46

What to do

Fix it during your normal patch cycle. No exploitation is confirmed yet.

  1. Check whether you run rustls rustls and which version.
  2. Update to a patched version listed above, then confirm the new version.

Timeline

  • Nov 8, 2026Published
  • Nov 9, 2026Record last modified

Score, severity and exploitation changes are tracked from the day Watchtower started logging them.

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Data last checked: Nov 14, 2026 02:13 UTC