CVE-2026-123610 json
rustls before 0.23.46 Denial of Service via Brotli Certificate Decompression
published 28d ago modified 2d ago also EUVD-2026-119369 , GHSA-h2v8-394m-p7vv , RUSTSEC-2026-0348
- cvss
- 3.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 5%
- public exploits
- 0
- none known
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.
Patch / fix
- crates.io rustls 0.23.46, 0.24.0-dev.2
- rustls rustls 0.23.46
- github.com/rustls/rustls@1aa987a commit
- github.com/rustls/rustls@402b7b7 commit
- github.com/rustls/rustls#3297 pull request
- github.com/rustls/rustls#3354 pull request
- github.com/rustls/rustls/releases/tag/v/0.23.46 release
Is CVE-2026-123610 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2d ago
Exploit prediction
0.17% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.3 | 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 |
| CNA | 3.1 | 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L |
| GitHub | 3.1 | 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L |
| CNA | 4.0 | 6.3 | 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/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 |
| OSV | 3.1 | 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| crates.io | rustls | <0.23.46 >=0.24.0-dev.1, <0.24.0-dev.2 >=0.23.9, <0.23.46 |
0.23.46 0.24.0-dev.2 |
Affected products
- rustls rustls
Classification
- Weakness
-
- CWE-770 Allocation of Resources Without Limits or Throttling
References
-
github.com
/rustls/rustls/pull/3297
web
-
github.com
/rustls/rustls/pull/3354
web
-
github.com
/rustls/rustls/commit/1aa987af37d0d79b98781d345895ac0059ce345c
web
-
github.com
/rustls/rustls/commit/402b7b78b7ae87d59e19cf07ee07f3fc19e6537e
web
-
github.com
/rustls/rustls/security/advisories/GHSA-h2v8-394m-p7vv
vendor-advisory, web
-
vulncheck.com
/advisories/rustls-before-0.23.46-denial-of-service-via-brotli-certificate-decompression
third-party-advisory
-
github.com
/rustls/rustls
package
-
github.com
/rustls/rustls/releases/tag/v/0.23.46
web
-
rustsec.org
/advisories/RUSTSEC-2026-0348.html
web, advisory
-
crates.io
/crates/rustls
package
Sources
- CVE List CVE-2026-123610
- GitHub Advisory GHSA-h2v8-394m-p7vv
- NVD CVE-2026-123610
- OSV RUSTSEC-2026-0348
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.