CVE-2026-59886: pyasn1 · Uncontrolled resource consumption when converting decoded REAL values
Affects s3qlSource GCVE Database
Not known to be exploited · CVSS 7.5 High : upgrade to 6.2.2_1 or 3.8.1 soon.
Data as of 1 Nov 2026, 01:50 UTC
- Patch
- Available – fixed in 6.2.2_1, 3.8.1
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 s3ql to 6.2.2_1 or 3.8.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrews3qlpkg:brew/s3qlOther 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
A patch is available and should be applied: upgrade to pyasn1 version 0.6.4 or s3ql versions 3.8.1 or 6.2.2_1 or later. The fix prevents large intermediate integer construction during float conversion and raises OverflowError for out-of-range values. As a workaround, avoid converting, printing, or comparing decoded Real objects from untrusted sources; instead, inspect the raw (mantissa, base, exponent) tuple directly.
Description
CVE-2026-59886 is a denial of service vulnerability in the pyasn1 library's handling of ASN.1 REAL values. The issue arises when converting decoded REAL values with very large exponents to Python floats, causing excessive CPU and memory consumption that can hang processes. This affects pyasn1 versions >=3.1 <3.8.1 and >=6.0.0 <6.2.2_1. The vulnerability is fixed in versions 3.8.1 and 6.2.2_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)