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CVE Record

CVE-2026-34993: AIOHTTP Vulnerable to Deserialization of Untrusted Data

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.14.0, using ``CookieJar.load()`` with untrusted input may allow arbitrary code execution. Most applications using this function will be doing so with the user's own data, so this is unlikely to affect many applications. Version 3.14.0 patches the issue. If an application does allow attacker controlled files to be loaded, a workaround on older releases would be to sanitize the files before loading.

HighCVSS 7.2Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This issue affects Python applications using aiohttp before 3.14.0. The risky case is narrow: loading an untrusted cookie jar file through CookieJar.load() may allow arbitrary code execution. The source notes most applications use this with the user’s own data, so broad exposure is unlikely.

Executive priority

Treat as high priority where aiohttp processes user-supplied files. For most environments, prioritize targeted inventory and upgrade rather than emergency response unless exposure is confirmed.

Technical view

CVE-2026-34993 is CWE-502 deserialization of untrusted data in aiohttp CookieJar.load() before 3.14.0. The published CVSS is 7.2 high with local access, high complexity, high privileges, user interaction, changed scope, and high confidentiality, integrity, and availability impact.

Likely exposure

Likely limited to Python services, tools, or automation using aiohttp below 3.14.0 and accepting attacker-controlled files or serialized cookie jar data for CookieJar.load().

Exploitation context

The supplied sources do not show CISA KEV listing or active exploitation. Exploitation depends on attacker-controlled input reaching CookieJar.load(), which the advisory suggests is uncommon in typical application use.

Researcher notes

Focus triage on data provenance into CookieJar.load(). Evidence supports patched version 3.14.0 and a sanitization workaround, but does not provide public exploitation details or broader affected products beyond aiohttp.

Mitigation direction

  • Upgrade aiohttp to version 3.14.0 or later.
  • Do not load attacker-controlled files with CookieJar.load().
  • Sanitize cookie jar files before loading on older releases.
  • Follow Red Hat advisories for packaged aiohttp updates.

Validation and detection

  • Inventory Python environments for aiohttp versions below 3.14.0.
  • Search application code for CookieJar.load() usage.
  • Confirm whether loaded cookie files can be attacker controlled.
  • Review containers and vendor packages for aiohttp dependencies.
Prepared
Confidence
high
Sources
9

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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cwe · medium confidence lookup

CWE-502: Code execution behavior lookup

Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2026-34993 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.2 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
9Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.2CVSS 3.1HighCVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H0.66redhat-SADP
6.4CVSS 3.1MediumCVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:C/C:L/I:H/A:L0.65.3GitHub_M

Vulnerability scoring details

Base CVSS 3.1 score

7.2High
CVSS 3.1 vector shape for CVE-2026-34993Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPaiohttp: AIOHTTP: Arbitrary code execution via untrusted input to CookieJar.load()
other:Red Hat severity ratingcvssV3_1
  • 2026-06-02T20:01:12.690Z: Reported to Red Hat.
  • 2026-06-02T18:29:15.847Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
aio-libsaiohttp< 3.14.0Listed
Weakness

CWE details

CWE-502

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.