VulnerabilityPublished 13 Aug 2026Updated 31 Oct 2026

CVE-2026-59886: pyasn1 · Uncontrolled resource consumption when converting decoded REAL values

Affects scoutsuiteSource GCVE Database

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Not known to be exploited · CVSS 7.5 High : upgrade to 5.14.0_15 soon.

Data as of 1 Nov 2026, 00:22 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 5.14.0_15

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade scoutsuite to 5.14.0_15.

Affected software

Product	Affected	Fixed in
Homebrewscoutsuite`pkg:brew/scoutsuite`Other threats	Affected >=5.13.0 <5.14.0_15	Fixed in 5.14.0_15

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 in pyasn1 version 0.6.4 that fixes the issue by safely handling large exponents during float conversion. Users should upgrade to this fixed version. As a workaround, avoid converting, printing, or comparing decoded Real objects from untrusted sources and instead inspect the raw (mantissa, base, exponent) tuple. Applications that do not handle ASN.1 REAL values are not affected.

Description

A vulnerability in pyasn1's univ.Real type causes excessive CPU and memory consumption when converting decoded REAL values with large exponents to Python floats. This can lead to denial of service when applications process untrusted ASN.1 data and perform float conversions such as printing or comparisons. The issue is fixed in pyasn1 version 0.6.4, which handles large exponents safely. Applications that do not handle ASN.1 REAL values or avoid converting these values from untrusted sources are not affected.

Impact

Denial of service due to uncontrolled resource consumption (CPU and memory) when converting specially crafted ASN.1 REAL values with large exponents to Python floats. This impacts applications that decode untrusted ASN.1 data and then convert these REAL values to floats for printing, logging, or comparison. The vulnerability does not affect decoding alone and does not compromise confidentiality or integrity.

Summary

The pyasn1 library's univ.Real type converts its (mantissa, base, exponent) tuple to a Python float using exact big-integer exponentiation. BER/CER/DER-encoded REAL values with large exponents cause the conversion to attempt materializing astronomically large integers, resulting in excessive CPU and memory use. This affects operations that trigger float conversion such as prettyPrint(), str(), comparisons, arithmetic, and explicit float() calls. The vulnerability can be exploited for denial of service by processing untrusted ASN.1 data. The flaw is present in pyasn1.type.univ.Real and reachable via pyasn1.codec.ber, cer, and der decoders. The issue is fixed in pyasn1 0.6.4 by using math.ldexp() for binary values and raising OverflowError for decimal values with out-of-range exponents, preventing large intermediate integer construction.

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Affected software

Description

AI analysisMachine-generated, updated 1 Nov 2026, 00:22 UTC

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