Code: void *hashtable_get(hashtable_t *hashtable, const char *key)
{
    pair_t *pair;
    size_t hash;
     bucket_t *bucket;
 
     hash = hash_str(key);
    bucket = &hashtable->buckets[hash % num_buckets(hashtable)];
 
     pair = hashtable_find_pair(hashtable, bucket, key, hash);
     if(!pair)
        return NULL;

    return pair->value;
}

Vulnerability Type: DoS 
CWE ID: CWE-310
Summary: Jansson, possibly 2.4 and earlier, does not restrict the ability to trigger hash collisions predictably, which allows context-dependent attackers to cause a denial of service (CPU consumption) via a crafted JSON document.
Commit Message: CVE-2013-6401: Change hash function, randomize hashes

Thanks to Florian Weimer and Eric Sesterhenn for reporting, reviewing
and testing.