CVE-2026-59886: pyasn1 · Uncontrolled resource consumption when converting decoded REAL values
Affects moleculeSource GCVE Database
Not known to be exploited · CVSS 7.5 High : upgrade to 26.6.0_1 or 3.0.5 soon.
Data as of 1 Nov 2026, 01:39 UTC
- Patch
- Available – fixed in 26.6.0_1, 3.0.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 13 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 31 Oct 2026.
What to do
Upgrade molecule to 26.6.0_1 or 3.0.5.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewmoleculepkg:brew/moleculeOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Apply the official patch by upgrading pyasn1 to version 3.0.5, 26.6.0_1, or later. If patching is not immediately possible, avoid converting, printing, or comparing decoded Real objects from untrusted sources; instead, inspect the raw (mantissa, base, exponent) tuple to prevent triggering the float conversion. The vulnerability is fixed in pyasn1 0.6.4 and subsequent releases.
Description
A vulnerability in the pyasn1 library's univ.Real type allows excessive CPU and memory consumption when converting decoded REAL values with large exponents to Python floats. This can cause denial of service if applications decode untrusted ASN.1 data and then convert, print, or compare these REAL values. The issue is fixed in pyasn1 versions 3.0.5 and 26.6.0_1.
References
- github.com/pyasn1/pyasn1/security/advisories/GHSA-hm4w-wwcw-mr6r (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-59886 (opens in a new tab)
- github.com/pyasn1/pyasn1/commit/e60c691cb91addb8fcefa2f537e85ede6fb1e886 (opens in a new tab)
- github.com/pyasn1/pyasn1 (opens in a new tab)
- github.com/pyasn1/pyasn1/releases/tag/v0.6.4 (opens in a new tab)